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Lennox International Inc. 51M37 Thermostat User Manual

1. SUNDAY PROGRAM 72 eo o 64 6AM NOON 6PM MID NIGHT Figure 10 NOTE Pressing the ENTER button during the following programming steps saves and exits to the HOME screen To program events and temperatures perform the follow ing steps Page 4 505067M 7 13 05 1 Press and release the PROG button MO Monday AM 6 00 period A COOL SETPOINT 78 and HEAT SETPOINT 70 are displayed AM 6 flashes 2 Use the Up Down arrow buttons to select the desired hour press the PROG button when the desired hour is reached use the Up Down arrow buttons again to select desired minute The selected hour minute is when the program will start Press the PROG button 3 Use the Up Down arrow buttons to select the desired heat setpoint press the PROG button 4 Use the Up Down arrow buttons to select the desired cool setpoint press the PROG button 5 Repeat steps 1 4 for Monday periods B C and D 6 COPY A PROGRAM If the program entered for Monday is satisfactory for other days of the week do the following to repeat the same program for other days A Press the PROG button then press the COPY button The display clears the screen except for Copy from MO with MO flashing Press the COPY button again to copy Monday s program B The display changes to Copy to MO Use the ar row buttons to scroll to the desired day where you want the same program a
2. Heat O Prog Day Time MO AM a A N an ata a LS HOLD AUTO eee OO ROOM SETPOINT m ao mess ne HERG Fan Hold OQ Settings Enter Figure 4 If the thermostat is in heat mode heat mode is disabled when the HEAT button is pressed This is indicated by OFF in the SYSTEM box as shown in figure 5 Heat Cool Mode Disabled ROOM SYSTEM ww x SETPOINT q md OI OFF Figure 5 Heating Demand Set the thermostat to heat mode to control the heating equipment Then if the room temperature is lower than the temperature setpoint as shown in figure 6 the thermostat detects a heating demand and will activate the heating equipment to satisfy the demand Heating Demand SYSTEM ROOM SETPOINT Ie u E HEAT Figure 6 Heating operation is indicated by a flame icon in the SYS TEM box When the actual temperature rises above the temperature setpoint the flame icon will disappear This indicates that the heating demand has been satisfied and that the heating equipment has been turned off NOTE Heating equipment is activated for at least 3 min utes if no buttons are pressed during the demand interval COOL Using the Cool Mode Enabling and Disabling Cool Mode Use the COOL button to enable or disable cool mode as desired If the thermostat is in HEAT or OFF mode cool mode is enabled when the COOL bu
3. 1 Ge neral ees iri tae aari iar A a tala evar eee 1 Introduction ein ea e Pak had eee diate 1 Initial Thermostat Power up 0055 1 Buttons Backlight Timers amp Settings 2 DAY TIME Set Day and Time 2 HEAT Heat Mode 220020 0205s 3 COOL Cool Mode 2202022000 3 AUTO Using the Autochangeover Mode 4 HOLD Temperature Hold Mode 4 PROG Thermostat Programming 4 COPY Copy a Program 2 2 0 6 FAN Controlling Fan Operation 5 Displaying Outside Temperature 6 SETTINGS Filter Maintenance Reminder 6 Service Indicator 0 002002eeeeeee 6 Thermostat RESET 2 22200200e0eee 6 Removing Installing Thermostat 7 Default Thermostat Settings 7 Thermostat Output Table 0000 7 Technical Specifications aaae anaana 8 Initial Power Up Display Copy tofrom MO TU WE TH FR SA SU PROG m e noaa am GOA a DA OA HOLD PM vs vs bal FANON M AUTO Yass COOL SETPOINT cs FILTER f SERVICE MAINTENANCE OUTPOOM o HEAT SESTI AN Figure 1 All display segments are momentarily activated This oc curs as a normal part of thermostat initialization 505 068M Within a few seconds the HOME screen appears see fig ure 2 with default settings as sho
4. Settings Enter a ww Outside J Figure 14 SETTINGS Filter Maintenance Reminders The 51M38 thermostat is designed to remind you when the filter needs changing or when routine maintenance is re quired as and if defined by you These optional remind ers are not enabled until you activate them To do so press the SETTINGS button once or twice for the desired re minder as shown in figure 15 and as described in table 1 Reminder Settings Display gt ry Ny MOS ad Ip For FILTER press SETTINGS button 1 time FILTER MAINTENANCE For MAINTENANCE press SETTINGS button 2 times Figure 15 Page 5 51M38 SERIES 5 2 The default setting for the reminders is OFF disabled Press Up Down arrow buttons to select the desired re minder intervals Buttons to Use SETTINGS 1st press then Arrows to scroll selections SETTINGS 2nd press then Arrows to scroll selections Table 1 Filter and Maintenance Reminders Reminder FILTER MAINTE NANCE Available Settings and How to Use Total fan run time expressed in months Off 1 3 6 12 for example if fan runs 12 hours a day 1 month reminder displays in 2 calendar months Elapsed chronological time in months Off 6 12 Use this for example to remind yourself when to perform routine checks or when to call a technician for perodic preventive maintenance Stores settings Enter NOTE The HOME s
5. 0 ve ROOM gt 0 m EC US o HEAT SETPOINT a m 0 Ra Peal v9 US Figure 8 Page 3 51M39 SERIES 5 2 NOTE If no buttons are pressed during a demand for cooling the equipment must operate for at least 4 minutes After a demand has been satisfied cooling equipment op eration is locked out for 5 minutes If another cooling de mand occurs during this 5 minute interval COOL and the snowflakes will flash however the cooling equipment will not operate until the 5 minute delay has elapsed AUTO Using the Autochangeover Mode When in either heat mode or cool mode autochangeover can be enabled or disabled by pressing the AUTO button If enabled AUTO appears at the lower right corner of the dis play The thermostat will then automatically change over from heating to cooling and vice versa to keep the room temperature in between the heating and cooling setpoints Autochangeover can be used in either of the thermostat hold modes or when the thermostat program is running These modes are described later HOLD Using Temperature Hold Modes When HOLD is displayed at the HOME screen the ther mostat is in a temperature hold condition This means that the temperature program data is ignored and the thermo stat functions much like a non programmable thermostat Adjusting Temperature Setpoint in Hold Mode The temperature setpoint represents the desired tempera ture of the space around the thermosta
6. FR SA and SU Press the DAY TIME button 4 The HOME screen reappears confirm day and time are correct This completes day and time setting Page 2 505067M 7 13 05 HEAT Using the Heat Mode Enabling and Disabling Heat Mode The thermostat must be in the heat mode to control the heating equipment Press the HEAT button to enable or disable heat mode If the thermostat is in cool or off mode pressing the HEAT button enables the heat mode indi cated by HEAT in the lower right corner see figure 4 Turn Heat ON OFF Heat Cool a ww Prog Auto o V ook Copy Day Time a a Fan Hold a d Y Settings Enter m y N a gt Y 5 Outside Figure 4 If the thermostat is in heat mode heat mode is disabled when the HEAT button is pressed This is indicated by OFF near the right side of the display as shown in figure 5 Heat Cool Mode Disabled ROOM w u HEAT SETPOINT y o k lt gt a Figure 5 Heating Demand Set the thermostat to heat mode to control the heating equipment Then if the room temperature is lower than the temperature setpoint as shown in figure 6 the thermostat detects a heating demand and will activate the heating equipment to satisfy the demand Heating Demand ROOM o HEAT SETPOINT 0 zim i _ SN C Figure 6 Heating operation is indicated by a flame icon in
7. SMALL X LARGE XIX Very LARGE Emergency X No Demand w Electric Backup outdoor sensor attached SMALL Above Balance Point X LARGE ABP Very LARGE ABP SMALL Below Balance Point LARGE BBP Very LARGE BBP Emergency X No Demand w Gas Backup dual fuel outdoor sensor attached SMALL ABP X X LARGE ABP xX X X Very LARGE ABP SMALL BBP LARGE BBP Very LARGE BBP Emergency No Demand Page 10 505050M 5 1 05 LENNOX J 2005 Lennox Industries Inc Dallas Texas USA i RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE 51M35 Merit Series Thermostat The Lennox Merit Series 5 2 day programmable electronic thermostat 51M35 provides excellent temperature control and a large easy to read display This product includes a programmable filter change reminder an equipment maintenance reminder and a system check indicator to notify the user when the equipment requires service Thermostat 51M35 is suitable for non heat pump two stage heat two stage cool applications using a gas or elec tric furnace These instructions are intended as a general guide and do not supersede local codes in any way Consult authorities having jurisdiction before installation Check equipment for shipping damage If you find any damage immediately contact the last carrier Introduction
8. tor terminals on the wall bracket Also when working with the thermostat dip switches use a non conductive tool and take cau tion to avoid making any contact with the circuit board its imprinted circuitry and its connector prongs Temperature Display Display Scale Fahrenheit or Celsius user selectable via DIP switch see figure 18 Display range 35 F 2 C to 99 F 37 C Display resolution 1 F 1 C Display Accuracy 1 F If the Fahrenheit Celsius display must be changed use a plastic non conductive tool to push the dip switch to the right position see figure 18 Changing Fahrenheit Celsius Setting N PLUG IN Use Care To Avoid Bending Prongs F C Fahrenheit Celsius switch shown in Celsius position Figure 18 Temperature Measurement Range Measurement Scale Fahrenheit Measurement Range 35 F to 99 F Measurement Resolution 0 5 F Measurement Accuracy 1 F Field Offset via DIP switches to 3 F Sampling Method temperature measurements sampled every 15 seconds Displayed temperature is the average of the last four measurements Temperature Setpoint Range Setting range 50 F 10 C to 90 F 32 C Setting resolution 1 F 1 C Smart Setback Recovery via DIP switch 6 Smart Setback Recovery SSR affects the way the ther mostat responds to program events If SSR is disabled the thermostat will react to a pro
9. 6 F Filter Reminder Settings of Off 1 3 6 or 12 months of fan run time are available When programmed time has elapsed a FILTER indicator is displayed Page 7 51M35 SERIES 5 2 Maintenance Reminder Settings of Off 6 or 12 months of chronological time are available When programmed time has elapsed a mainte nance indicator MAINT is displayed Service Reminder The SERVICE indicator is displayed only under the follow ing conditions e ifthe thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the R terminal OR e if the thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the C terminal Power Loss Recovery Thermostat memory is retained for a minimum of 24 hours during a power loss includes retention of program infor mation HOLD status programmed temperature setpoint heat cool and fan mode settings filter reminder status maintenance reminder status and equipment protection timers After 24 hours of power loss programmed settings will be lost and replaced with default settings A IMPORTANT Power must be applied for at least six consecutive hours prior to a power loss in order for memory to be retained for the specified time LCD Backlight Activated for 30 seconds when any button is pressed NOTE During an electrical storm or similar disturbance the backlight may acti
10. This document describes the operation of Lennox thermostat 51M35 Refer to the installation manual for instructions re garding installation and wiring of the thermostat Initial Thermostat Power up When power is initially applied to the thermostat the dis play will appear as shown in figure 1 05 05 Page 1 OPERATION MANUAL 51M35 Merit Series 5 2 Day Programmable Thermostat CONTROLS 1E Technical 505 049M Publications 05 05 Litho U S A Supersedes 03 05 Table of Contents 51M35 Series Thermostat 2 1 General vies ake sa sime ead eben eee dues bad ada 1 Introduction 0200 cece eee eee eee 1 Initial Thermostat Power up 005 1 Buttons Backlight Timers amp Settings 2 DAY TIME Set Day and Time 2 HEAT Heat Mode 2 02200005 3 COOL Cool Mode 220202000 0 3 HOLD Temperature Hold Mode 4 PROG Thermostat Programming 4 FAN Controlling Fan Operation 5 SETTINGS Filter Maintenance Reminder 5 Service Indicator 0 00200e eee eeee 6 Thermostat RESET 2 22200200eeeee 6 Removing Installing Thermostat 6 Default Thermostat Settings 6 Technical Specifications 00 000 ue 7 Thermostat Output Table 8 Initial Power Up Display MO TU WE TH FR
11. initiated or terminated using the UP DOWN HEAT or COOL buttons Equipment Protection Override Both the minimum compressor OFF timer and the mini mum equipment cycle timer can be over ridden by press ing and holding either the HEAT or COOL button down for 4 seconds Over Temperature Protection Thermal mechanical switch opens W1 at 93 F 6 F Filter Reminder Settings of Off 1 3 6 or 12 months of fan run time are available When programmed time has elapsed a FILTER indicator is displayed Maintenance Reminder Settings of Off 6 or 12 months of chronological time are available When programmed time has elapsed a MAIN TENANCE indicator is displayed Service Reminder The SERVICE indicator is displayed only under the follow ing conditions e ifthe thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the R terminal OR e ifthe thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the C terminal Power Loss Recovery Thermostat memory is retained for a minimum of 24 hours during a power loss includes retention of clock setting program information HOLD status programmed temper ature setpoint heat cool and fan mode settings filter re minder status maintenance reminder status and equip ment protection timers After 24 hours of power loss programmed settings will be lost and replaced with
12. 1 05 05 Page 1 OPERATION MANUAL 51M34 Merit Series 5 2 Day Programmable Thermostat CONTROLS 1E Technical 505 048M Publications 05 05 Litho U S A Supersedes 03 05 Table of Contents 51M34 Series Thermostat 2 1 General vies ake es ume eae Swe eee dues bad eee 1 Introduction 020 0c cece e eee eee 1 Initial Thermostat Power up 005 1 Buttons Backlight Timers amp Settings 2 DAY TIME Set Day and Time 2 HEAT Heat Mode 2 02200005 3 COOL Cool Mode 220020220 eee 3 HOLD Temperature Hold Mode 4 PROG Thermostat Programming 4 FAN Controlling Fan Operation 5 SETTINGS Filter Maintenance Reminder 5 Service Indicator 0 002002 eee eeee 6 Thermostat RESET 2 20 0020 eee eee 6 Removing Installing Thermostat 6 Default Thermostat Settings 6 Technical Specifications 0 000 ue 7 Thermostat Output Table 8 Initial Power Up Display MO TU WE TH FR SA SU Ta m 0 AM DnA 08 8 PM Cus Dat vs FAN PROGENEJLIDI HOLD ON AUTO SYSTEM COOL amp a oO nag ma 0 8 8 ae EMG Hi Wal tat HEAT Lo OM SETPOINT Figure 1 All display segments are momentarily activated This oc curs as a normal part of thermostat init
13. 3 Outside J Figure 15 SETTINGS Filter Maintenance Reminders The 51M39 thermostat is designed to remind you when the filter needs changing or when routine maintenance is re quired as and if defined by you These optional remind ers are not enabled until you activate them To do so press the SETTINGS button once or twice for the desired re minder as shown in figure 16 and as described in table 1 Reminder Settings Display gt a yy MOS ed Ip For FILTER press SETTINGS button 1 time FILTER MAINTENANCE For MAINTENANCE press SETTINGS button 2 times Figure 16 The default setting for the reminders is OFF disabled Press Up Down arrow buttons to select the desired re minder intervals Table 1 Filter and Maintenance Reminders Buttons to Use Settings 1st press then Arrows to scroll selections Settings 2nd press then Arrows to scroll selections Reminder FILTER MAINTE NANCE Available Settings and How to Use Total fan run time expressed in months Off 1 3 6 12 for example if fan runs 12 hours a day 1 month reminder displays in 2 calendar months Elapsed chronological time in months Off 6 12 Use this for example to remind yourself when to perform routine checks or when to call a technician for perodic preventive maintenance Enter Stores settings NOTE The HOME screen will reappear about 15 seconds
14. SMALL Heat Demand LARGE lt lt X lt X lt Heat Setpoint Perm Hold 70 F or 21 C Cool Demand SMALL Cool Setpoint Perm Hold 78 F or 26 C Xx X lt X gt lt Cool Demand LARGE Fan Auto No Demand Filter Reminder OFF Electric Heat Continuous Fan Maintenance Reminder OFF Heat Demand SMALL X Equipment Protection Timers Reset Back to Zero Heat Demand LARGE X Autochangeover OFF Table 3 Default Program Settings Time amp Temp Programs All days A Time Temp Heat 70 F 21 C Temp Cool 78 F 26 C All days B 62 F 17 C 85 F 29 C All days C 70 F 21 C 78 F 26 C All days D 62 F 17 C 82 F 28 C Thermostat Output Table Table 4 depicts the 51M39 thermostat output states for var ious input conditions The following notes described terms used in the table Cool Demand SMALL Cool Demand LARGE No Demand NOTE X output is activated with 24VAC NOTE The temperature ranges expressed in the follow ing definitions of SMALL LARGE demands are for guid ance only actual temperatures may vary With a SMALL heat demand temperature is below setpoint 0 5F but above setpoint 1 5F AND 30 minute upstage timer HAS NOT expired With a LARGE heat demand temperature is less than s
15. Settings Time amp Temp Programs All days A Time Temp Heat 70 F 21 C Temp Cool 78 F 26 C All days B 62 F 17 C 85 F 29 C All days C 70 F 21 C 78 F 26 C All days D 62 F 17 C 82 F 28 C Thermostat Output Table Table 4 depicts the 51M38 thermostat output states for var ious input conditions Table 4 Thermostat Outputs Condition w1 Gas Heat Auto Fan Heat Demand Cool Demand No Demand Gas Heat Continuous Fan Heat Demand Cool Demand No Demand Electric Heat Auto Fan Heat Demand Cool Demand No Demand Electric Heat Continuous Fan Heat Demand X Cool Demand X No Demand NOTE X output is activated with 24VAC Technical Specifications Thermostat Type Electronic programmable thermostat for 1 Stage Heat 1 Stage Cool gas or electric heat non heat pump non power robbing applications Power Supply Range 18VAC 30VAC 24VAC nominal 60Hz 4 CAUTION 24VAC is present on the terminals of the thermostat bracket If removing the thermostat from the wall use caution and avoid touching any of the connec tor terminals on the wall bracket Also when working with the thermostat dip switches use a non conductive tool and take cau tion to avoid making any contact with the circuit board its imprinted circuitry and its connector EER Temperature Di
16. Temporary Hold press HOLD once to switch to Permanent Hold HOLD displays solid PROG not dis played press HOLD again to return to the program PROG displays HOLD not displayed Temporary Hold Temperature Mode _ Heat Cool ook Prog Auto Copy Day Time mo o LL ug W A HOD sn mN COOLSETFONT y x AUTO wy e ak e 5 cos cs ROOM HEAT SETPOINT ons tE 68 Fan Hold x Settings Enter r o Outside Figure 9 PROG Thermostat Programming The 51M38 thermostat can be programmed to perform a set of both heating and cooling events for each day of the week Each day can be programmed for 4 unique events per day and each day can be different from any other day To Set Program Events and Temperatures Figure 10 gives an example of how up to 7 different pro grams can be set Programs A and C reflect the desired warmth while the home IS occupied 72 B allows less heating while the home is NOT occupied D reflects a cool sleeping temperature NOTE The example in figure 10 shows heat setpoints a similar program may be set for cool setpoints Program Example MONDAY PROGRAM 72 68 64 TUESDAY PROGRAM 72 68 64 WEDNESDAY PROGRAM 72 68 64 lo B THURSDAY PROGRAM 72 3 68 64 FRIDAY PROGRAM 72 ae ioe 64 SATURDAY PROGRAM 72 68 64 B
17. The temperature setpoint represents the desired tempera ture of the space around the thermostat The default heat setpoint in hold mode is 70 F the default cool setpoint in hold mode is 78 F To adjust the setpoint press the UP or DOWN A V arrow buttons see figure 8 the existing setpoint is displayed to the right of the actual room temperature Each button press adjusts the setpoint up or down by 1 degree Hold Temperature Mode Heat Cool Prog Auto ook mo CMa Sa AM ia HoD US OOS COOLSETFONT 3 ee k f icco Copy Day Time Vlse Settings Enter cr Outside Figure 8 After the desired setpoint is reached the HOME screen will reappear after about 15 seconds Permanent Hold Mode At any time the program is running from the HOME screen set a permanent hold program override by press ing the HOLD button see figure 8 The thermostat now functions much like a non programmable thermostat Use the Up Down arrow buttons to adjust the hold setpoint To return to the program press HOLD again Temporary 2 Hour Hold At any time the program is running from the HOME screen set a temporary 2 hour hold by pressing the Up Down arrow buttons until the desired setpoint is displayed HOLD flashes see figure 9 This overrides the program for 2 hours from the last button press then returns to the program While in
18. WE TH FR SA SU PROG ome 2 DEGE AM r HOLD pM 6 Mafa FAN coo setPoint AUTO we RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE 51M39 Merit Series Thermostat The Lennox Merit Series 7 day programmable electronic thermostat 51M39 provides excellent temperature control and a large easy to read display This product includes a programmable filter change reminder an equipment maintenance reminder and a system check indicator to notify the user when the equipment requires service Thermostat 51M39 is suitable for non heat pump two stage heat two stage cool applications using a gas or elec tric furnace Also the thermostat provides autochange over capability These instructions are intended as a general guide and do not supersede local codes in any way Consult authorities having jurisdiction before installation Check equipment for shipping damage If you find any damage immediately contact the last carrier Introduction This document describes the operation of Lennox thermo stat 51M39 Refer to the installation manual for instructions regarding installation and wiring of the thermostat Initial Thermostat Power up When power is initially applied to the thermostat the dis play will appear as shown in figure 1 07 05 Page 1 OPERATION MANUAL 51M39 Merit Series 7 Day Programmable Thermostat Technical Conros Ma 07 05 Litho U S A Table of Contents 51M39 Series Thermostat
19. a general guide and do not supersede local codes in any way Consult authorities having jurisdiction before installation Check equipment for shipping damage If you find any damage immediately contact the last carrier Introduction This document describes the operation of Lennox thermo stat 51M38 Refer to the installation manual for instructions regarding installation and wiring of the thermostat Initial Thermostat Power up When power is initially applied to the thermostat the dis play will appear as shown in figure 1 07 05 Page 1 OPERATION MANUAL 51M38 Merit Series 7 Day Programmable Thermostat Technical poner ee 07 05 Litho U S A Table of Contents 51M38 Series Thermostat 0 1 General aes ii eee ote b pce Pare ee 1 Introduction ein ea betas Paks E otis 1 Initial Thermostat Power up 0055 1 Buttons Backlight Timers amp Settings 2 DAY TIME Set Day and Time 2 HEAT Heat Mode 2 22 22200 eee 3 COOL Cool Mode 2220220005 3 AUTO Using the Autochangeover Mode 3 HOLD Temperature Hold Mode 4 PROG Thermostat Programming 4 COPY Copy a Program 2 0 5 FAN Controlling Fan Operation 5 Displaying Outside Temperature 5 SETTINGS Filter Maintenance Reminder 5 Service Indicator 0 00200
20. and cool for 5 consecutive days using a set of 4 unique events per day The remaining 2 days can then be set for a different set of 4 unique events per day Both the consecutive days and the events temperature are set by the homeowner To Change Consecutive Days To alter the 5 consecutive days press and hold the PROG button for 5 seconds The 5 consecutive day period is then displayed default is MOnday thru FRiday To change to a different 5 consecutive days use the Up Down arrow buttons Any 5 consecutive day span may be selected for example in figure 14 Saturday through Wednesday is defined as the 5 day programming Thurs day and Friday would constitute the 2 day programming Press the PROG button when finished Change Consecutive days MO TU WE SA SU Figure 14 To Set Program Events and Temperatures Figure 15 gives an example of how the two sets of pro grams can be set for a normal workweek and weekend In the 5 day bar graph note how programs A and C reflect the desired warmth while the home IS occupied 72 B allows less heating while the home is NOT occupied D re flects a cooler sleeping temperature The 2 day bar graph would support day long occupancy and because the first program begins later a less demanding time schedule 5 2 Program rampie 5 DAY PROGRAM A B C 72 68 64 2 DAY PROGRAM 72 68 64 6AM NOON 6PM MID NIGHT Figure 15 NOTE Pressin
21. and the temperature setting appears for 15 seconds If desired start making changes within 15 sec onds or the HOME screen will return The backlight will turn off 15 seconds after the HOME screen reappears DAY TIME Setting the Day and Time Press the DAY TIME button and set the CURRENT hour minute and day of week as follows 1 am12 will flash on the screen Press the UP DOWN arrows to change the hour AM or PM must corre spond to time of day Press DAY TIME OR if adjust ing for daylight savings time pressing ENTER stores the single change and exits to the HOME screen by passing minutes and day of week 2 Minutes will flash Use the UP DOWN arrow button to display the minutes past the hour Press DAY TIME 3 Day MO Monday will flash Use UP or DOWN arrow buttons to display the current day Day selections are abbreviated as MO TU WE TH FR SA and SU Press DAY TIME 4 The HOME screen reappears confirm day and time are correct This completes day and time setting Page 2 505048M 5 1 05 HEAT Using the Heat Mode Enabling and Disabling Heat Mode The thermostat must be in the HEAT mode to control the heating equipment Press the Heat button to enable or dis able HEAT mode If the thermostat is in COOL or OFF mode pressing the Heat button enables the HEAT mode indicated by HEAT in the SYSTEM box see figure 4 Turn Heat ON OFF
22. button to enable or disable cool mode as desired If the thermostat is in HEAT or OFF mode cool mode is enabled when the COOL button is pressed This is indicated by COOL in the SYSTEM box see figure 9 Turn Cool ON OFF MO AM Mn TAA Fany Nal nad VS vv HOLD auto Day Time SYSTEM ROOM 5 SETPOINT COOL 1 ire A 8 O OQ Settings Enter QO 2 Figure 9 If the thermostat is in cool mode pressing the Cool button disables COOL mode indicated by OFF in the SYSTEM box see figure 10 Cool Mode Disabled SYSTEM ROOM SETPOINT OFF k kar D Us Figure 10 Cooling Demand Set the thermostat to cool mode to control the cooling equipment Then if the room temperature is higher than the temperature setpoint as shown in figure 11 the ther mostat detects a cooling demand and will activate the cool ing equipment to satisfy the demand Cooling Demand gt D Pane Ub a 4 08 US HOLD MO d AM SYSTEM COOL x ak Bea o SETPOINT are q T Hi Figure 11 Cooling operation is indicated by flashing snowflake icons in the SYSTEM box When the actual temperature drops below the temperature setpoint the snowflake icons will disappear This indicates that the cooling demand has been satisfied and that the cooling equipment has been turned off If your system supports 2 stage cooling a
23. buttons to select the desired temperature setpoint press PROG 5 Repeat steps 2 through 4 for periods B C and D 6 Repeat steps 1 through 5 for the 2 day program Page 4 505048M 5 1 05 NOTE This thermostat will NOT automatically switch from heating to cooling or vice versa operator involve ment is required At the change of seasons or to accomo date abnormal seasonal temperature swings you must manually select to the opposite conditioning Heat or Cool program FAN Controlling the Fan Operation Use the FAN button to select either continuous fan mode or auto fan mode To change from continuous to auto fan mode or vice ver sa press the FAN button Note whether a fan icon in the FAN box is present indicating that the fan is running or not fan not running If continuous fan mode is enabled ON displayed in FAN box see figure 13 the fan will run continuously regard less of whether the heating or cooling equipment is run ning Using Fan ON Heat Cool OC O Prog Day Time OC Fan Hold O Settings Enter QQ Figure 13 If auto fan mode is selected AUTO displayed in FAN box see figure 14 the fan will only run when the heating or cooling equipment is running Using Fan Auto Heat AM na oF Wot Z PROG E AUTO QQ Prog Day Time a Settings Enter A Figure 14 SETTINGS Filter Maintenance Reminders The 51M34 thermostat is designed t
24. default settings A IMPORTANT Power must be applied for at least six consecutive hours prior to a power loss in order for memory to be retained for the specified time LCD Backlight Activated for 30 seconds when any button is pressed NOTE During an electrical storm or similar disturbance the backlight may activate for a few seconds This is nor mal and will no longer occur after the electrical disturbance has passed Thermostat Operating Conditions 35 F to 105 F 5 to 90 RH Thermostat Storage Conditions 40 F to 185 F 5 to 95 RH Page 8 505067M 7 13 05
25. during the following programming steps saves and exits to the HOME screen To program events and temperatures perform the follow ing steps 1 Press and release the PROG button MO Monday AM 6 00 period A COOL SETPOINT 78 and HEAT SETPOINT 70 are displayed AM 6 flashes 2 Use the Up Down arrow buttons to select the desired hour press the PROG button when the desired hour is reached use the Up Down arrow buttons again to select desired minute The selected hour minute is when the program will start Press the PROG button 3 Use the Up Down arrow buttons to select the desired heat setpoint press the PROG button 4 Use the Up Down arrow buttons to select the desired cool setpoint press the PROG button 5 Repeat steps 1 4 for Monday periods B C and D 6 COPY A PROGRAM If the program entered for Monday is satisfactory for other days of the week do the following to repeat the same program for other days A Press the PROG button then press the COPY button The display clears the screen except for Copy from MO with MO flashing Press the COPY button again to copy Monday s program B The display changes to Copy to MO Use the ar row buttons to scroll to the desired day where you want the same program as Monday Press the COPY button C Repeat steps A and B for as many days as you want the same program 4 Copy a Programmed Day to Another Day Heat Coo
26. in figure 13 shows heat setpoints a similar program may be set for cool setpoints 1 Press and release the PROG button MO Monday AM 6 00 period A COOL SETPOINT 78 and HEAT SETPOINT 70 are displayed AM 6 flashes 2 Use the Up Down arrow buttons to select the desired hour press the PROG button when the desired hour is reached use the Up Down arrow buttons again to select desired minute The selected hour minute is when the program will start Press the PROG button 3 Use the Up Down arrow buttons to select the desired heat setpoint press the PROG button 4 Use the Up Down arrow buttons to select the desired cool setpoint press the PROG button NOTE Pressing the ENTER button during the following programming steps saves and exits to the HOME screen To program events and temperatures perform the follow ing steps Page 5 Program Example MONDAY PROGRAM 72 68 64 TUESDAY PROGRAM WEDNESDAY PROGRAM THURSDAY PROGRAM FRIDAY PROGRAM SATURDAY PROGRAM SUNDAY PROGRAM D 6 6AM NOON 6PM MID NIGHT Figure 13 5 Repeat steps 1 4 for Monday periods B C and D 6 COPY A PROGRAM If the program entered for Monday is satisfactory for other days of the week do the following to repeat the same program for other days A Press the PROG button then press the COPY button The display clears the screen except fo
27. interval has elapsed the remind er will be displayed as shown in figure 16 Reminders FAN Figure 16 After the filter has been changed reset the filter reminder by pressing the SETTINGS button for 4 seconds The screen will blink for a few moments to indicate that the tim er has been reset Page 5 51M34 SERIES 5 2 Service Indicator When abnormal equipment operation is detected the SERVICE indicator will flash on the screen see figure 17 This indicates that the equipment requires service from a qualified service technician Service Indicator Flashing MO el FA a d T i d bd mM SERVICE i Ofl a FAN PROG mE Auto ROOM SYSTEM o Ca Hear Figure 17 Thermostat RESET Under some abnormal conditions it may be necessary to reset the thermostat to its default condition Such a RE SET would delete all programming and settings and there fore should only be used on rare occasions when the the thermostat fails to function as designd and or as pro grammed Such an instance can occur as a result of a pow er surge or similar electrical disturbance e g after an elec trical storm or power outage The RESET button can be used to recover from this situation 4 CAUTION When the RESET button is pressed ALL settings re vert back to the defaults including the default pro gram see tables 2 and 3 The RESET button is an unlabeled recessed button lo cated behind the door on th
28. is enabled via the AUTO button the thermostat will automatically change over from heating to cooling and vice versa to keep the room temperature in between the heating and cooling setpoints The deadband is the minimum difference between the heating and cooling setpoints Fan Control AUTO or ON modes gas or electric heat compatible via DIP switches also see Thermostat Output section 1 0 Relays All thermostat relays are latching type to minimize power consumption Equipment Protection Timers Minimum Compressor OFF time 5 minutes Minimum Compressor ON time 4 minutes Minimum Furnace ON time 3 minutes Minimum furnace cycle time elapsed time between any furnace activation and the next furnace activation 6 min utes Minimum elapsed time between any compressor activa tion and the next compressor activation 6 minutes Page 8 505068M 07 05 NOTE All protection timers except the compressor OFF timer can be over ridden if a heating or cooling demand is initiated or terminated using the UP DOWN HEAT or COOL buttons Equipment Protection Override Both the minimum compressor OFF timer and the mini mum equipment cycle timer can be over ridden by press ing and holding either the HEAT or COOL button down for 4 seconds Over Temperature Protection Thermal mechanical switch opens W1 and W2 at 93 F 6 F Filter Reminder Settings of Off 1 3 6 or 12 months of fan run time are available When programmed t
29. not dis played press HOLD again to return to the program PROG displays HOLD not displayed PROG Thermostat Programming The 51M35 thermostat can be programmed to perform a set of either heating or cooling events but not a combination of heat and cool for 5 consecutive days using a set of 4 unique events per day The remaining 2 days can then be set for a different set of 4 unique events per day Both the consecutive days and the events temperature are set by the homeowner To Change Consecutive Days To alter the 5 consecutive days press and hold the PROG button for 5 seconds The existing 5 consecutive day peri od is then displayed default is MOnday thru FRiday To change to a different 5 consecutive days use the Up Down arrow buttons Any 5 consecutive day span may be selected for example in figure 11 Saturday through Wednesday is defined as the 5 day programming Thurs day and Friday would constitute the 2 day programming Press the PROG button when finished Change Consecutive days SA SU MO TU WE Figure 11 To Set Program Events and Temperatures Figure 12 gives an example of how the two sets of pro grams can be set for a normal workweek and weekend In the 5 day bar graph note how programs A and C reflect the desired warmth while the home IS occupied 72 B allows less heating while the home is NOT occupied D re flects a cool sleeping temperature The 2 day bar graph would support day lon
30. times to access the Bal ance Point Settings screen see figure 20 Balance Point Setting SETPOINT ad ae mh ad Figure 20 The balance point can be set at any temperature between 1 F and 55 F 17 C to 13 C A balance point setting of zero disables the balance point function in this case the thermostat behaves as if no outdoor sensor is attached The default balance point setting is 55 F To adjust the balance point up or down press the Up Down arrow buttons to the right of the display screen The bal ance point setting increases by 1 F each time the Up but ton is pressed and decreases by 1 F each time the Down button is pressed After the desired balance point is reached the HOME screen will reappear after about 15 seconds NOTE The balance point feature allows the outdoor tem perature to rise or fall 3 F above or below the balance point This prevents excessive cycling of the equipment when the outdoor temperature is near the balance point For example if the balance point is 40 F and the actual outdoor temperature is 35 F the outdoor temperature must rise to 43 F before equipment adjustment occurs Conversely if the balance point is 40 F and the actual out door temperature is 45 F the outdoor temperature must drop to 37 F before equipment adjustment occurs Service Indicator When abnormal equipment operation is detected the SERVICE indicator will flash on the screen see figure 21 Th
31. 85 F 29 C Weekend C 70 F 21 C 78 F 26 C Weekend D 62 F 17 C 82 F 28 C Monday Tuesday Wednesday Thursday Friday Page 6 505048M 5 1 05 Saturday Sunday Technical Specifications Thermostat Type Electronic programmable thermostat for 1 Stage Heat 1 Stage Cool gas or electric heat non heat pump non power robbing applications Power Supply Range 18VAC 30VAC 24VAC nominal 60Hz 4 CAUTION 24VAC is present on the terminals of the thermostat bracket If removing the thermostat from the wall use caution and avoid touching any of the connec tor terminals on the wall bracket Also when working with the thermostat dip switches use a non conductive tool and take cau tion to avoid making any contact with the circuit board its imprinted circuitry and its connector prongs Temperature Display Display Scale Fahrenheit or Celsius user selectable via DIP switch see figure 18 Display range 35 F 2 C to 99 F 37 C Display resolution 1 F 1 C Display Accuracy 1 F If the Fahrenheit Celsius display must be changed use a plastic non conductive tool to push the dip switch to the right position see figure 18 Changing Fahrenheit Celsius Setting N PLUG IN Use Care To Avoid Bending Prongs F C Fahrenheit Celsius switch shown in Celsius position Figure 18 Tempe
32. Balance Point LARGE BBP VERY LARGE BBP Emergency X No Demand With Gas Backup dual fuel outdoor senso r attached SMALL ABP X X LARGE ABP X X X VERY LARGE ABP SMALL BBP LARGE BBP VERY LARGE BBP Emergency No Demand Technical Specifications Thermostat Type Electronic programmable thermostat for heat pump 3 stage heat 2 stage cool NOTE 2 stages of heat pump heat and one stage of auxil iary gas or electric backup heat are supported Power Supply Range 18VAC 30VAC 24VAC nominal 60Hz 4 CAUTION 24VAC is present on the terminals of the thermostat bracket If removing the thermostat from the wall use caution and avoid touching any of the connec tor terminals on the wall bracket Also when working with the thermostat dip switches use a non conductive tool and take cau tion to avoid making any contact with the circuit board its imprinted circuitry and its connector ER Temperature Display Display Scale Fahrenheit or Celsius user selectable via DIP switch see figure 21 Display range 35 F 2 C to 99 F 37 C Display resolution 1 F 1 C Display Accuracy 1 F If the Fahrenheit Celsius display must be changed use a plastic non conductive tool to push the dip switch to the right position see figure 21 Changing Fahrenheit Celsius Setting PLUG IN Use Car
33. EAT Using the Heat Mode Enabling and Disabling Heat Mode The thermostat must be in the HEAT mode to control the heating equipment Press the Heat button to enable or dis able HEAT mode If the thermostat is in COOL or OFF mode pressing the Heat button enables the HEAT mode indicated by HEAT in the SYSTEM box see figure 4 Turn Heat ON OFF 0 O Prog Day Time MO AM E A n att ad VS HOLD auto wee OC ROOM o SETPOINT ROM be min O Hear Fan Hold OO Settings Enter QQ 7 Figure 4 If the thermostat is in heat mode pressing the Heat button disables HEAT mode indicated by OFF in the SYSTEM box see figure 5 Heat Cool Mode Disabled ROOM SYSTEM w x SETPOINT i pad OI OFF Figure 5 Heating Demand Set the thermostat to heat mode to control the heating equipment Then if the room temperature is lower than the temperature setpoint as shown in figure 6 the thermostat detects a heating demand and will activate the heating equipment to satisfy the demand Heating Demand SYSTEM ROOM SETPOINT Ie u K HEAT Figure 6 Heating operation is indicated by a flame icon in the SYS TEM box When the actual temperature rises above the temperature setpoint the flame icon will disappear This indicates that the heating demand has been satisfied and that the heating equip
34. Heat Mode In normal heat mode both the heat pump and the backup heat source are used to provide heat If the thermostat de tects that the heat pump is not able to provide enough heat as may be the case in very cold weather then the backup heat source is activated Emergency Heat Mode In emergency heat mode only the backup heat source provides heat the heat pump is disabled The backup heat source is activated only when there is a heat demand Enabling Normal Heat Mode Use the HEAT button to select normal heat mode emer gency heat mode or to disable heat modes as desired If the thermostat is in off or cool mode pressing the HEAT button enables heat mode This is indicated by HEAT in the lower right corner see figure 4 Normal Heat Mode Enabled Heat Cool a Lf Prog Auto a a ww ww ook Copy Day Time a a V Fan Hold a a T Y Settings Enter m o Outside Figure 4 Enabling Emergency Heat Mode If the thermostat is in heat mode pressing the HEAT button enables emergency heat mode see figure 5 If the ther mostat is in normal heat mode when the HEAT button is pressed then emergency heat mode is enabled Emergency Heat Mode Enabled ROOM ay ap HEAT SETPOINT rr bal Dam 1 b Figure 5 Disabling Heat Mode If the thermostat is in emergency heat mode when the HEAT button is pressed then heat modes are disabled This is indicate
35. LENNOX J 2005 Lennox Industries Inc Dallas Texas USA RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE 51M37 Merit Series Thermostat The Lennox Merit Series 5 2 day programmable electronic thermostat 51M37 provides excellent temperature control and a large easy to read display It includes a programmable filter change reminder an equipment maintenance reminder and a system check indicator to notify the user when the equipment requires service The 51M37 is suitable for heat pump 3 stage heat 2 stage cool applications using a gas or electric auxiliary heat source An optional outdoor temperature sensor provides auxiliary heat lockout balance point operation and dual fuel compatibility These instructions are intended as a general guide and do not supersede local codes in any way Consult authorities having jurisdiction before installation Check equipment for shipping damage If you find any damage immediately contact the last carrier Introduction This document describes the operation of Lennox thermostat 51M37 Refer to the installation manual for instructions re garding installation and wiring of the thermostat Initial Thermostat Power up When power is initially applied to the thermostat the dis play will appear as shown in figure 1 05 05 Page 1 OPERATION MANUAL 51M37 Merit Series 5 2 Day Programmable Thermostat CONTROLS 1E Technical Publications eae Litho U S A Supersede
36. ROOM gt 0 m v8 0S Cooling operation is indicated by flashing snowflake icons When the actual temperature drops below the tem perature setpoint the snowflake icons will disappear This indicates that the cooling demand has been satisfied and that the cooling equipment has been turned off If your system supports 2 stage cooling as does the 51M42 thermostat you may notice various cooling levels being delivered during a demand Also if a small cooling demand is present Lo will be displayed in the SYSTEM box However if a large cooling demand is present Hi will be displayed in the lower right side of the display shown in figure 10 NOTE If no buttons are pressed during a demand for cooling the equipment must operate for at least 4 minutes After a demand has been satisfied cooling equipment op eration is locked out for 5 minutes If another cooling de mand occurs during this 5 minute interval COOL and the snowflakes will flash however the cooling equipment will not operate until the 5 minute delay has elapsed AUTO Using the Autochangeover Mode When in either heat mode or cool mode autochangeover can be enabled or disabled by pressing the AUTO button If enabled AUTO appears at the lower right corner of the dis play The thermostat will then automatically change over from heating to cooling and vice versa to keep the room temperature in between the heating and cooling setpoints Au
37. RVICE i Ofl a FAN PROG mE Auto ROOM SYSTEM o Ca Hear Figure 17 Thermostat RESET Under some abnormal conditions it may be necessary to reset the thermostat to its default condition Such a RE SET would delete all programming and settings and there fore should only be used on rare occasions when the the thermostat fails to function as designd and or as pro grammed Such an instance can occur as a result of a pow er surge or similar electrical disturbance e g after an elec trical storm or power outage The RESET button can be used to recover from this situation 4 CAUTION When the RESET button is pressed ALL settings re vert back to the defaults including the default pro gram see tables 2 and 3 The RESET button is an unlabeled recessed button lo cated behind the door on the right hand side of the thermo stat below the SETTINGS button see figure 3 Use a pa per clip or small pencil to press the RESET button ALL thermostat settings will be reset to the defaults listed in the Default Thermostat Settings section Removing and installing Thermostat The thermostat hinges on tabs on the top of the subbase no tool is needed to remove the thermostat from the sub base Pivot the bottom of the thermostat outward releas ing the snaps then lift up to remove To install it first position the top tilted toward the wall brack et and align it until you feel the tabs and slots enga
38. SA SU Ta m 0 AM DnA 08 8 PM Cus Dat vs FAN PROGENEJLIDI HOLD ON AUTO SYSTEM COOL amp a oO nag ma 0 8 8 ae EMG Hi Wal tat HEAT Lo OM SETPOINT Figure 1 All display segments are momentarily activated This oc curs as a normal part of thermostat initialization 505 049M Within a few seconds the Home Screen appears see fig ure 2 with default settings as shown After about 1 minute of initialization time the actual room temperature will be displayed NOTE Tables 2 and 3 on page 6 show all system and programming defaults Home Screen MO a on AM D A q me vs vs FAN HOLD AUTO SYSTEM ROOM o a Cus HEAT Figure 2 At this point the thermostat will be fully functional its de fault temperature setpoint not shown is 70 F At this point if the equipment has been fully powered and if a heat demand were present the system would begin operating NOTE Temperature scale default is Fahrenheit units but may be reset to show Celsius if desired See page 7 Buttons Backlight Timers amp Settings Buttons are located behind the small door on the right hand side of the thermostat see figure 3 A IMPORTANT Do NOT begin pressing buttons until after you read the following section describing each button A pale blue display backlight illuminates for 30 seconds each time any button is pressed When PROG or DAY TIME is pressed a field begins flas
39. Use the Up Down arrow buttons to adjust the hold setpoint To return to the program press the HOLD button again Page 4 505069M 07 05 Temporary 2 Hour Hold At any time the program is running from the HOME screen set a temporary 2 hour hold by pressing the Up Down arrow buttons until the desired setpoint is displayed HOLD flashes see figure 12 This overrides the pro gram for 2 hours from the last button press then returns to the program Temporary Hold Temperature Mode _ Heat Cool Prog Auto Copy Day Time ee Fan Hold ook Settings Enter cr o Outside Figure 12 While in Temporary Hold press the HOLD button once to switch to Permanent Hold HOLD displays solid PROG not displayed press the HOLD button again to return to the program PROG displays HOLD not displayed PROG Thermostat Programming The 51M42 thermostat can be programmed to perform a set of both heating and cooling events for each day of the week Each day can be programmed for 4 unique events per day and each day can be different from any other day To Set Program Events and Temperatures Figure 13 gives an example of how up to 7 different pro grams can be set Programs A and C reflect the desired warmth while the home IS occupied 72 B allows less heating while the home is NOT occupied D reflects a cool sleeping temperature NOTE The example
40. ae _ ib Q QO hs 2 me Prog Day Time vrs AUTO sve OC S me SETPOINT Sp Fan Hold ie e OL Settings Enter OO Figure 12 After the desired setpoint is reached the HOME screen will reappear after about 15 seconds Permanent Hold Mode At any time the program is running from the HOME screen set a permanent hold program override by press ing the HOLD button see figure 12 The thermostat now functions much like a non programmable thermostat Use the Up Down arrow buttons to adjust the hold setpoint To return to the program press HOLD again Temporary 2 Hour Hold At any time the program is running from the HOME screen set a temporary 2 hour hold by pressing the Up Down arrow buttons until the desired setpoint is displayed HOLD flashes see figure 13 This overrides the pro gram for 2 hours from the last button press then returns to the program Temporary Hold Temperature Mode QQ Prog Day Time MO MD ea COs Proc E gt ot LINES i SETPOINT COOL Be i sts Settings Enter OO Figure 13 While in Temporary Hold press HOLD once to switch to Permanent Hold HOLD displays solid PROG not dis played press HOLD again to return to the program PROG displays HOLD not displayed PROG Thermostat Programming The 51M37 thermostat can be programmed to perform a set of either heating or cooling events but not a combination of heat
41. after the final arrow button press OR press the ENTER button at any time to store any changes and exit to the HOME screen After either programmed interval has elapsed the remind er will be displayed as shown in figure 17 Reminders MO am O SOS HOLD FAN AUTO ROOM ww wo Filter amp Maintenance Indicators FAN AUTO _ _ BMH ROOM w f Gi lt A Service Indicator Flashing Figure 17 After the filter has been changed or maintenance per formed reset the reminder by pressing the SETTINGS button for 4 seconds at the corresponding reminder set tings screen The screen will blink for a few moments to in dicate that the timer has been reset Service Indicator When abnormal equipment operation is detected the SERVICE indicator will flash on the screen see figure 17 This indicates that the equipment requires service from a qualified service technician Thermostat RESET Under some abnormal conditions it may be necessary to reset the thermostat to its default condition Such a RE SET would delete all programming and settings and there fore should only be used on rare occasions when the the thermostat fails to function as designed and or as pro grammed Such an instance can occur as a result of a pow er surge or similar electrical disturbance e g after an elec trical storm or power outage The RESET button can be used to recover from this situation 4 CAUTION When t
42. and How to Use Total fan run time expressed in months Off 1 3 6 12 for example if fan runs 12 hours a day 1 month reminder displays in 2 calendar months Elapsed chronological time in months Off 6 12 Use this for example to remind yourself when to perform routine checks or when to call a technician for perodic preventive maintenance Stores settings Enter NOTE The HOME screen will reappear about 15 seconds after the final arrow button press OR press ENTER at any time to store any changes and exit to the HOME screen After either programmed interval has elapsed the remind er will be displayed as shown in figure 19 Reminders FAN AUTO SYSTEM Figure 19 After the filter has been changed or maintenance per formed reset the reminder by pressing the SETTINGS button for 4 seconds The screen will blink for a few mo ments to indicate that the timer has been reset Page 6 505050M 5 1 05 SETTINGS Balance Point NOTE The balance point is only available with the out door sensor If the optional outdoor sensor X2658 is connected to the thermostat balance point adjustment is available The bal ance point feature allows the measured outdoor tempera ture to govern operation of the heat pump and backup heat source Use the SETTINGS button to access the balance point setting If the outdoor sensor is attached to the thermostat press the SETTINGS button three
43. backlight will turn off 15 seconds after the HOME screen reappears DAY TIME Setting the Day and Time Press the DAY TIME button and set the CURRENT hour minute and day of week as follows 1 am12 will flash on the screen Press the UP DOWN arrows to change the hour AM or PM must corre spond to time of day Press DAY TIME OR if adjust ing for daylight savings time pressing the ENTER but ton stores the single change and exits to the HOME screen bypassing minutes and day of week 2 Minutes will flash Use the UP DOWN arrow button to display the minutes past the hour Press DAY TIME 3 Day MO Monday will flash Use UP or DOWN arrow buttons to display the current day Day selections are abbreviated as MO TU WE TH FR SA and SU Press DAY TIME 4 The HOME screen reappears confirm day and time are correct This completes day and time setting Page 2 505068M 07 05 HEAT Using the Heat Mode Enabling and Disabling Heat Mode The thermostat must be in the heat mode to control the heating equipment Press the HEAT button to enable or disable HEAT mode If the thermostat is in cool or off mode pressing the HEAT button enables the heat mode indicated by HEAT in the lower right corner see figure 4 Turn Heat ON OFF Heat Cool oN ww ook Prog Auto ed Copy Day Time amp wwe HEAT SETPONT cc Fan Hold oo a a ww
44. changes within 15 seconds or the HOME screen will re turn Thermostat Buttons Heat Cool T V Prog Auto a amp wo ook Fan Hold wo Settings Enter m o Outside Figure 3 When an Arrow HOLD HEAT or COOL button is pressed SETPOINT and the temperature setting appears for 15 seconds If desired start making changes within 15 sec onds or the HOME screen will return The backlight will turn off 15 seconds after the HOME screen reappears DAY TIME Setting the Day and Time Press the DAY TIME button and set the CURRENT hour minute and day of week as follows 1 am12 will flash on the screen Press the Up Down ar rows buttons to change the hour AM or PM must correspond to time of day Press DAY TIME OR if ad justing for daylight savings time pressing the ENTER button stores the single change and exits to the HOME screen bypassing minutes and day of week 2 Minutes will flash Use the Up Down arrow buttons to display the minutes past the hour Press DAY TIME 3 Day MO Monday will flash Use Up Down arrow buttons to display the current day Day selections are abbreviated as MO TU WE TH FR SA and SU Press DAY TIME 4 The HOME screen reappears confirm day and time are correct This completes day and time setting Page 2 505069M 07 05 HEAT Using the Heat Mode Normal
45. creen will reappear about 15 seconds after the final arrow button press OR press the ENTER button at any time to store any changes and exit to the HOME screen After either programmed interval has elapsed the remind er will be displayed as shown in figure 16 Reminders MO am O SOS S ae D HOLD FAN AUTO FILTER ROOM Wy o gt Cus FAN autan l Banas ROOM ae gt Filter amp Maintenance Indicators Service Indicator Flashing Figure 16 After the filter has been changed or maintenance per formed reset the reminder by pressing the SETTINGS button for 4 seconds at the corresponding reminder set tings screen The screen will blink for a few moments to in dicate that the timer has been reset Service Indicator When abnormal equipment operation is detected the SERVICE indicator will flash on the screen see figure 16 This indicates that the equipment requires service from a qualified service technician Thermostat RESET Under some abnormal conditions it may be necessary to reset the thermostat to its default condition Such a RE SET would delete all programming and settings and there fore should only be used on rare occasions when the the thermostat fails to function as designed and or as pro grammed Such an instance can occur as a result of a pow er surge or similar electrical disturbance e g after an elec trical storm or power outage Th
46. ctivated with 24VAC for at least 5 minutes AND the L terminal is shorted to the C terminal Power Loss Recovery Thermostat memory is retained for a minimum of 24 hours during a power loss includes retention of program infor mation HOLD status programmed temperature setpoint heat cool and fan mode settings filter reminder status maintenance reminder status and equipment protection timers After 24 hours of power loss programmed settings will be lost and replaced with default settings A IMPORTANT Power must be applied for at least six consecutive hours prior to a power loss in order for memory to be retained for the specified time LCD Backlight Activated for 30 seconds when any button is pressed NOTE During an electrical storm or similar disturbance the backlight may activate for a few seconds This is nor mal and will no longer occur after the electrical disturbance has passed Thermostat Operating Conditions 35 F to 105 F 5 to 90 RH Thermostat Storage Conditions 40 F to 185 F 5 to 95 RH Page 9 51M37 SERIES 5 2 Thermostat Output Table Table 5 depicts the 51M37 thermostat output states for var ious input conditions The following notes described terms used in the table NOTES e X output is activated with 24VAC BBP outdoor temperature is below balance point e ABP outdoor temperature is above balance point e In all cases the state of the B terminal is opposite that of the O te
47. d LARGE No Demand Electric Heat Continuous Fan HEAT Demand SMALL X HEAT Demand LARGE X X COOL Demand SMALL COOL Demand LARGE No Demand Page 8 505049M 5 1 05 LENNOX J 2005 Lennox Industries Inc Dallas Texas USA RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE 51M34 Merit Series Thermostat The Lennox Merit Series 5 2 day programmable electronic thermostat 51M34 provides excellent temperature control and a large easy to read display This product includes a programmable filter change reminder an equipment maintenance reminder and a system check indicator to notify the user when the equipment requires service Thermostat 51M34 is suitable for non heat pump single stage heat single stage cool applications with either gas or electric furnace These instructions are intended as a general guide and do not supersede local codes in any way Consult authorities having jurisdiction before installation Check equipment for shipping damage If you find any damage immediately contact the last carrier Introduction This document describes the operation of Lennox thermostat 51M34 Refer to the installation manual for instructions re garding installation and wiring of the thermostat Initial Thermostat Power up When power is initially applied to the thermostat the dis play will appear as shown in figure
48. d by OFF near the right side of the display as shown in figure 6 Heat Mode Disabled ROOM HEAT SETPOINT 1 e D 3 Figure 6 Heating Demand The thermostat must be in either normal or emergency heat mode in order to properly control the heating equip ment In either heat mode when the actual temperature is lower than the temperature setpoint as shown in figure 7 the thermostat detects a heating demand and activates the heating equipment to satisfy the demand Heating opera tion is indicated by a flame icon in bottom right hand corner of the display Heating Demand eg CM q A HEAT SETPOINT xz LR 7 9 Figure 7 When the actual temperature rises above the temperature setpoint the flame icon will disappear This indicates that the heating demand has been satisfied and that the heat ing equipment has been turned off Heat pump operation is locked out for 5 minutes after a de mand has been satisfied If another heat pump demand occurs during this 5 minute interval the flame icon will flash however the heat pump will not run until the 5 min ute delay has elapsed NOTE The heat pump is activated for at least 4 minutes if no buttons are pressed during the demand interval The backup heat source is activated for at least 3 minutes if no buttons are pressed during the demand interval If your system supports 3 stage heating as does the 51M42 thermostat you may notice various heating leve
49. e Settings Enter cr 6 Outside Figure 4 If the thermostat is in heat mode heat mode is disabled when the HEAT button is pressed This is indicated by OFF near the right side of the display as shown in figure 5 Heat Cool Mode Disabled ROOM nd o HEAT SETPOINT P a al Figure 5 Heating Demand Set the thermostat to heat mode to control the heating equipment Then if the room temperature is lower than the temperature setpoint as shown in figure 6 the thermostat detects a heating demand and will activate the heating equipment to satisfy the demand Heating Demand ROOM i o HEAT SETPOINT 1y kar a ao Figure 6 Heating operation is indicated by a flame icon in the lower right corner When the actual temperature rises above the temperature setpoint the flame icon will disappear This indicates that the heating demand has been satisfied and that the heating equipment has been turned off If your system supports 2 stage heating as does the 51M39 thermostat you may notice various heating levels being delivered during a demand NOTE Heating equipment is activated for at least 3 min utes if no buttons are pressed during the demand interval COOL Using the Cool Mode Enabling and Disabling Cool Mode Use the COOL button to enable or disable cool mode as desired If the thermostat is in heat or off mode cool mode is enabled when the COOL button is press
50. e a a wwe Fan Hold eo wa Figure 16 Displaying Outside Temperature Pressing the ENTER Outside button at the HOME screen displays the outside temperature see figure 17 for several seconds then returns to room temperature Check Outside Temperature Settings Enter bod Outside y Figure 17 SETTINGS Filter Maintenance Reminders The 51M42 thermostat is designed to remind you when the filter needs changing or when routine maintenance is re quired as and if defined by you These optional remind ers are not enabled until you activate them To do so press the SETTINGS button shown below the FAN button in fig ure 16 once or twice for the desired reminder as shown in figure 18 and as described in table 1 Reminder Settings Display gt a yy MOS ad sp For FILTER press SETTINGS button 1 time FILTER MAINTENANCE For MAINTENANCE press SETTINGS button 2 times Figure 18 The default setting for the reminders is OFF disabled Press Up Down arrow buttons to select the desired re minder intervals Table 1 Filter and Maintenance Reminders Buttons to Use Settings 1st press then Arrows to scroll selections Settings 2nd press then Arrows to scroll selections Reminder FILTER MAINTE NANCE Available Settings and How to Use Total fan run time expressed in months Off 1 3 6 12 for example if fan runs 12 hours a day 1
51. e in figure 11 Saturday through Wednesday is defined as the 5 day programming Thurs day and Friday would constitute the 2 day programming Press the PROG button when finished Change Consecutive days SA SU MO TU WE Figure 11 To Set Program Events and Temperatures Figure 12 gives an example of how the two sets of pro grams can be set for a normal workweek and weekend In the 5 day bar graph note how programs A and C reflect the desired warmth while the home IS occupied 72 B allows less heating while the home is NOT occupied D re flects a cool sleeping temperature The 2 day bar graph would support day long occupancy and because the first program begins later a less demanding time schedule 5 2 Program Example 5 DAY PROGRAM A D 72 68 64 MID 6AM NIGHT 2 DAY PROGRAM D 72 68 ia 64 6AM NOON 6PM MID NIGHT Figure 12 NOTE Pressing ENTER during the following program ming steps saves and exits to the HOME screen To program events and temperatures perform the follow ing steps once with Cool selected and once with Heat se lected 1 Press and release PROG am 6 00 period A and the 5 consecutive days are displayed am 6 flashes 2 Use the Up Down arrow buttons to select the desired hour press PROG when the desired hour is reached 3 Use the Up Down arrow buttons to select the desired minute press PROG 4 Use the Up Down arrow
52. e 1 Filter and Maintenance Reminders Buttons to Use Settings 1st press then Arrows to scroll selections Settings 2nd press then Arrows to scroll selections Reminder FILTER Available Settings and How to Use Total fan run time expressed in months Off 1 3 6 12 for example if fan runs 12 hours a day 1 month reminder displays in 2 calendar months Elapsed chronological time in months Off 6 12 Use this for example to remind yourself when to perform routine checks or when to call a technician for perodic preventive maintenance Stores settings Enter NOTE The HOME screen will reappear about 15 seconds after the final arrow button press OR press ENTER at any time to store any changes and exit to the HOME screen After either programmed interval has elapsed the remind er will be displayed as shown in figure 16 Reminders FAN Figure 16 After the filter has been changed or maintenance per formed reset the reminder by pressing the SETTINGS button for 4 seconds The screen will blink for a few mo ments to indicate that the timer has been reset Page 5 51M35 SERIES 5 2 Service Indicator When abnormal equipment operation is detected the SERVICE indicator will flash on the screen see figure 17 This indicates that the equipment requires service from a qualified service technician Service Indicator Flashing MO el FA a d T i d bd mM SE
53. e 7 the thermostat detects a heating demand and activates the heating equipment to satisfy the demand Heating opera tion is indicated by a flame icon in the SYSTEM box Heating Demand SYSTEM BOOM SETPOINT Ie Oa cs Figure 7 a HEAT When the actual temperature rises above the temperature setpoint the flame icon will disappear This indicates that the heating demand has been satisfied and that the heat ing equipment has been turned off Heat pump operation is locked out for 5 minutes after a de mand has been satisfied If another heat pump demand occurs during this 5 minute interval the flame icon will flash however the heat pump will not run until the 5 min ute delay has elapsed NOTE The heat pump is activated for at least 4 minutes if no buttons are pressed during the demand interval The backup heat source is activated for at least 3 minutes if no buttons are pressed during the demand interval If your system supports 3 stage heating as does the 51M37 thermostat you may notice various heating levels being delivered during a demand If a small heat pump heating demand is present Lo is dis played in the SYSTEM box if a large heat pump heating demand is present Hi is displayed see figure 8 Large Heat Demand ROOM ay way o gt gt SETPOINT Figure 8 Page 3 51M37 SERIES 5 2 COOL Using the Cool Mode Enabling and Disabling Cool Mode Use the COOL
54. e RESET button can be used to recover from this situation 4 CAUTION When the RESET button is pressed ALL settings re vert back to the defaults including the default pro gram see tables 2 and 3 The RESET button is an unlabeled recessed button lo cated behind the door on the right hand side of the thermo stat below the SETTINGS button see figure 3 Use a pa per clip or small pencil to press the RESET button ALL thermostat settings will be reset to the defaults listed in the Default Thermostat Settings section Removing Installing Thermostat The thermostat hinges on tabs on the top of the subbase no tool is needed to remove the thermostat from the sub base Pivot the bottom of the thermostat outward releas ing the snaps then lift up to remove To replace it first position the top tilted toward the wall bracket and align it until you feel the tabs and slots engage then while the top is in place pivot the bottom toward the wall until the thermostat snaps into place Default Thermostat Settings Default thermostat settings are in table 2 and the default program is shown in table 3 Table 2 Mode Heat Perm Hold Heat Setpoint Perm Hold 70 F or 21 C Cool Setpoint Perm Hold 78 F or 26 C Fan Auto OFF OFF Reset Back to Zero OFF Filter Reminder Maintenance Reminder Equipment Protection Timers Autochangeover Page 6 505067M 7 13 05 Table 3 Default Program
55. e To Avoid Bending Prongs F C Fahrenheit Celsius switch shown in Celsius position Figure 21 Indoor Temperature Measurement Range Measurement Scale Fahrenheit Measurement Range 35 F to 99 F Measurement Resolution 0 5 F Measurement Accuracy 1 F Field Offset via DIP switches to 3 F Sampling Method temperature measurements sampled every 15 seconds Displayed temperature is the average of the last four measurements Outdoor Temperature Measurement Range Measurement Scale Fahrenheit Measurement Range 22 F to 122 F Measurement Resolution 1 F Measurement Accuracy 2 F Temperature Setpoint Range Setting range 50 F 10 C to 90 F 32 C Setting resolution 1 F 1 C Smart Setback Recovery via DIP switch 6 Smart Setback Recovery SSR affects the way the ther mostat responds to program events If SSR is disabled the thermostat will react to a program event at the time the event occurs However if SSR is enabled the thermostat will react to a program event before the event occurs such that the desired temperature is reached at the time of the event not after Autochangeover Deadband Selection via DIP switch 7 Autochangeover deadband can be set to 4 or 6 degrees When autochangeover is enabled via the AUTO button the thermostat will automatically change over from heating to cooling and vice versa to keep the room temperature in between the heating and cooling setpoin
56. e right hand side of the thermo stat below the SETTINGS button see figure 3 Use a pa per clip or small pencil to press the RESET button ALL thermostat settings will be reset to the defaults listed in the Default Thermostat Settings section Removing Installing Thermostat The thermostat hinges on tabs on the top of the subbase no tool is needed to remove the thermostat from the sub base Pivot the bottom of the thermostat outward releas ing the snaps then lift up to remove To replace it first position the top tilted toward the wall bracket and align it until you feel the tabs and slots engage then while the top is in place pivot the bottom toward the wall until the thermostat snaps into place Default Thermostat Settings Default thermostat settings are in table 2 and the default program is shown in table 3 Table 2 Default Thermostat Settings Mode Heat Permanent Hold Mode 70 F or 21 C Setpoint Fan Auto OFF OFF Reset Back to Zero Filter Reminder Maintenance Reminder Equipment Protection Timers Table 3 Default Program Settings Programs Weekday A Time Temperature Heat 70 F 21 C Temperature Cool 78 F 26 C Weekday B 62 F 17 C 85 F 29 C Weekday C 70 F 21 C 78 F 26 C Weekday D Weekend A 62 F 17 C 70 F 21 C 82 F 28 C 78 F 26 C Weekend B 62 F 17 C
57. e times to access the Bal ance Point Settings screen see figure 20 Balance Point Setting The balance point can be set at any temperature between 1 F and 55 F 17 C to 13 C A balance point setting of zero disables the balance point function in this case the thermostat behaves as if no outdoor sensor is attached The default balance point setting is 55 F To adjust the balance point up or down press the Up Down arrow buttons to the right of the display screen The bal ance point setting increases by 1 F each time the Up but ton is pressed and decreases by 1 F each time the Down button is pressed After the desired balance point setting is reached the HOME screen will reappear after about 15 seconds NOTE The balance point feature allows the outdoor tem perature to rise or fall 3 F above or below the balance point This prevents excessive cycling of the equipment when the outdoor temperature is near the balance point For example if the balance point is 40 F and the actual outdoor temperature is 35 F the outdoor temperature must rise to 43 F before equipment adjustment occurs Conversely if the balance point is 40 F and the actual out door temperature is 45 F the outdoor temperature must drop to 37 F before equipment adjustment occurs Service Indicator When abnormal equipment operation is detected the SERVICE indicator will flash on the screen see figure 19 on page 7 This indicates that the equip
58. ed This is indi cated by COOL on the right side of the display see figure 8 Turn Cool ON OFF Heat Cool aN O Prog Auto T V ook COOLSETFONT yh ak Pe k p ea Cr HEAT SETPOINT ja Fan Hold z a ec F Settings Enter cr a a S Outside Figure 7 If the thermostat is in cool mode pressing the COOL but ton disables cool mode indicated by OFF in the SYSTEM box see figure 5 Cooling Demand Set the thermostat to cool mode to control the cooling equipment Then if the room temperature is higher than the temperature setpoint as shown in figure 7 the thermo stat detects a cooling demand and will activate the cooling equipment to satisfy the demand Cooling operation is indicated by flashing snowflake icons on the right side of the display When the actual tem perature drops below the temperature setpoint the snow flake icons will disappear This indicates that the cooling demand has been satisfied and that the cooling equipment has been turned off If your system supports 2 stage cooling as does the 51M39 thermostat you may notice various cooling levels being delivered during a demand Also if a small cooling demand is present Lo will be displayed in the SYSTEM box However if a large cooling demand is present Hi will be displayed in the lower right corner shown in figure 8 Cooling Demand COOL SETPOINT w
59. eee eens 6 Thermostat RESET 2 220020000eee 6 Removing Installing Thermostat 6 Default Thermostat Settings 6 Thermostat Output Table 00005 7 Technical Specifications 00 eee 7 Initial Power Up Display Copy tofrom MO TU WE TH FR SA SU PROG m e noaa am GOA a DA A HOLD PM vs vs v8 FANON M AUTO Yass COOL SETPOINT cs FILTER f SERVICE MAINTENANCE OUTPOOM A EO AN Figure 1 o All display segments are momentarily activated This oc curs as a normal part of thermostat initialization 505 067M Within a few seconds the HOME screen appears see fig ure 2 with default settings as shown After about 1 minute of initialization time the actual room temperature will be displayed HOME Screen Figure 2 At this point the thermostat will be fully functional its de fault temperature setpoint not shown is 70 F At this point if the equipment has been fully powered and if a heat demand were present the system would begin operating NOTE Temperature scale default is Fahrenheit units but may be reset to show Celsius if desired See page 7 Buttons Backlight Timers amp Settings Buttons are located behind the small door on the right hand side of the thermostat see figure 3 A IMPORTANT Do NOT begin pressing buttons until after you read the following section describing each button A
60. enance reminder status and equip ment protection timers After 24 hours of power loss programmed settings will be lost and replaced with default settings A IMPORTANT Power must be applied for at least six consecutive hours prior to a power loss in order for memory to be retained for the specified time LCD Backlight Activated for 30 seconds when any button is pressed NOTE During an electrical storm or similar disturbance the backlight may activate for a few seconds This is nor mal and will no longer occur after the electrical disturbance has passed Thermostat Operating Conditions 35 F to 105 F 5 to 90 RH Thermostat Storage Conditions 40 F to 185 F 5 to 95 RH Page 10 505069M 07 05 LENNOX J 2005 Lennox Industries Inc Dallas Texas USA MO TU WE TH FR SA SU RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE 51M38 Merit Series Thermostat The Lennox Merit Series 7 day programmable electronic thermostat 51M38 provides excellent temperature control and a large easy to read display This product includes a programmable filter change reminder an equipment maintenance reminder and a system check indicator to notify the user when the equipment requires service Thermostat 51M38 is suitable for non heat pump single stage heat single stage cool applications with either gas or electric furnace Also the thermostat provides auto changeover capability These instructions are intended as
61. ent before the event occurs such that the desired temperature is reached at the time of the event not after Autochangeover Deadband Selection via DIP switch 7 Autochangeover deadband can be set to 4 or 6 degrees When autochangeover is enabled via the AUTO button the thermostat will automatically change over from heating to cooling and vice versa to keep the room temperature in between the heating and cooling setpoints The deadband is the minimum difference between the heating and cooling setpoints Fan Control AUTO or ON modes gas or electric heat compatible via DIP switches also see Thermostat Output section 1 0 Relays All thermostat relays are latching type to minimize power consumption Table 5 51M38 Terminal Designations Description 24VAC First stage cooling First stage heating Fan control Service Indicator 24VAC common Outdoor temperature sensor connection 1 Terminal Outdoor temperature sensor connection 2 Equipment Protection Timers Minimum Compressor OFF time 5 minutes Minimum Compressor ON time 4 minutes Minimum Furnace ON time 3 minutes Minimum furnace cycle time elapsed time between any furnace activation and the next furnace activation 6 min utes Minimum elapsed time between any compressor activa tion and the next compressor activation 6 minutes NOTE All protection timers except the compressor OFF timer can be over ridden if a heating or cooling demand is
62. ention of program infor mation HOLD status programmed temperature setpoint heat cool and fan mode settings filter reminder status maintenance reminder status and equipment protection timers After 24 hours of power loss programmed settings will be lost and replaced with default settings A IMPORTANT Power must be applied for at least six consecutive hours prior to a power loss in order for memory to be retained for the specified time LCD Backlight Activated for 30 seconds when any button is pressed NOTE During an electrical storm or similar disturbance the backlight may activate for a few seconds This is nor mal and will no longer occur after the electrical disturbance has passed Thermostat Operating Conditions 35 F to 105 F 5 to 90 RH Thermostat Storage Conditions 40 F to 185 F 5 to 95 RH Thermostat Output Table Table 5 depicts the 51M34 thermostat output states for var ious input conditions Table 5 Thermostat Outputs Condition w1 Gas Heat Auto Fan HEAT Demand COOL Demand No Demand Gas Heat Continuous Fan HEAT Demand COOL Demand No Demand Electric Heat Auto Fan HEAT Demand COOL Demand No Demand Electric Heat Continuous Fan HEAT Demand X COOL Demand X No Demand NOTE X output is activated with 24VAC Page 8 505048M 5 1 05 LENNOX J 2005 Lennox Industries Inc Dallas Texas USA MO TU
63. er Supply Range 18VAC 30VAC 24VAC nominal 60Hz 4 CAUTION 24VAC is present on the terminals of the thermostat bracket If removing the thermostat from the wall use caution and avoid touching any of the connec tor terminals on the wall bracket Also when working with the thermostat dip switches use a non conductive tool and take cau tion to avoid making any contact with the circuit board its imprinted circuitry and its connector WO ER Temperature Display Display Scale Fahrenheit or Celsius user selectable via DIP switch see figure 22 Display range 35 F 2 C to 99 F 37 C Display resolution 1 F 1 C Display Accuracy 1 F If the Fahrenheit Celsius display must be changed use a plastic non conductive tool to push the dip switch to the right position see figure 22 Changing Fahrenheit Celsius Setting N PLUG IN Use Care To Avoid Bending Prongs F C Fahrenheit Celsius switch shown in Celsius position Figure 22 Temperature Measurement Range Measurement Scale Fahrenheit Measurement Range 35 F to 99 F Measurement Resolution 0 5 F Measurement Accuracy 1 F Field Offset via DIP switches to 3 F Sampling Method temperature measurements sampled every 15 seconds Displayed temperature is the average of the last four measurements Temperature Setpoint Range Setting range 50 F 10 C to 90 F 32 C Settin
64. er Up Display Copy tofrom MO TU WE TH FR SA SU PROG a a noaa am COA a DA A HOLD PM v8 v8 vs FANON M AUTO Yass COOL SETPOINT a FILTER f SERVICE MAINTENANCE hyp ages o HEAT FEESTE AN Figure 1 All display segments are momentarily activated This oc curs as a normal part of thermostat initialization 505 069M Within a few seconds the HOME screen appears see fig ure 2 with default settings as shown After about 1 minute of initialization time the actual room temperature will be displayed NOTE Tables 2 and 3 on page 8 show all system and programming defaults HOME Screen Figure 2 At this point the thermostat will be fully functional its de fault temperature setpoint not shown is 70 F At this point if the equipment has been fully powered and if a heat demand were present the system would begin operating NOTE Temperature scale default is Fahrenheit units but may be reset to show Celsius if desired See page 9 Buttons Backlight Timers amp Settings Buttons are located behind the small door on the right hand side of the thermostat see figure 3 A IMPORTANT Do NOT begin pressing buttons until after you read the following section describing each button A pale blue display backlight illuminates for 30 seconds each time any button is pressed When PROG or DAY TIME button is pressed a field be gins flashing expecting another input Start making
65. etpoint 1 5F OR 30 minute upstage timer HAS expired With a SMALL cool demand temperature is above setpoint 0 5F but below setpoint 1 5F AND 30 minute upstage timer HAS NOT expired With a LARGE cool demand temperature is above setpoint 1 5F OR 30 minute upstage timer HAS expired Page 7 51M39 SERIES 5 2 Technical Specifications Thermostat Type Electronic programmable thermostat for 2 Stage gas or electric Heat 2 Stage Cool non heat pump non power robbing applications Table 5 Res WeWAGS vi Frststage coin Wi Frststage hain Y2 Secona stage coin woo is Second stage heating Service Indicator 24VAC common Outdoor temperature sensor connection 1 Outdoor temperature sensor connection 2 Power Supply Range 18VAC 30VAC 24VAC nominal 60Hz 4 CAUTION 24VAC is present on the terminals of the thermostat bracket If removing the thermostat from the wall use caution and avoid touching any of the connec tor terminals on the wall bracket Also when working with the thermostat dip switches use a non conductive tool and take cau tion to avoid making any contact with the circuit board its imprinted circuitry and its connector prongs Temperature Display Display Scale Fahrenheit or Celsius user selectable via DIP switch see figure 18 Changing Fahrenheit Celsius Setting PLUG IN Use Care To Avoid Bending Prongs F C Fahrenheit Celsius switch
66. ext furnace activation 6 min utes Minimum elapsed time between any compressor activa tion and the next compressor activation 6 minutes NOTE All protection timers except the compressor OFF timer can be over ridden if a heating or cooling demand is initiated or terminated using the UP DOWN HEAT or COOL buttons Equipment Protection Override Both the minimum compressor OFF timer and the mini mum equipment cycle timer can be over ridden by press ing and holding either the HEAT or COOL button down for 4 seconds Over Temperature Protection Thermal mechanical switch opens W1 at 93 F 6 F Filter Reminder Settings of Off 1 3 6 or 12 months of fan run time are available When programmed time has elapsed a FILTER indicator is displayed Page 7 51M34 SERIES 5 2 Maintenance Reminder Settings of Off 6 or 12 months of chronological time are available When programmed time has elapsed a mainte nance indicator MAINT is displayed Service Reminder The SERVICE indicator is displayed only under the follow ing conditions e ifthe thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the R terminal OR e ifthe thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the C terminal Power Loss Recovery Thermostat memory is retained for a minimum of 24 hours during a power loss includes ret
67. fan mode or vice ver sa press the FAN button Note whether a fan icon in the FAN box is present indicating that the fan is running or not fan not running If continuous fan mode is enabled ON displayed in FAN box see figure 13 the fan will run continuously regard less of whether the heating or cooling equipment is run ning Using Fan ON Cool QQ Prog Day Time OC Fan Hold O Settings Enter OO Figure 13 If auto fan mode is selected AUTO displayed in FAN box see figure 14 the fan will only run when the heating or cooling equipment is running Using Fan Auto Heat AM Mn SU jar Cs i PROG EJ AUTO ROOM foo aa X Settings Enter OO Figure 14 SETTINGS Filter Maintenance Reminders The 51M35 thermostat is designed to remind you when the filter needs changing or when routine maintenance is re quired as and if defined by you These optional remind ers are not enabled until you activate them To do so press the Settings button shown below the Fan button in figure 14 once or twice for the desired reminder as shown in fig ure 15 and as described in table 1 Reminder Settings Display _ For MAINT yu Nad MAINT press Settings button 2 times ome Figure 15 The default setting for the reminders is OFF disabled Press Up Down arrow buttons to select the desired re minder intervals For FILTER press Settings button 1 time Tabl
68. g ENTER during the following program ming steps saves and exits to the HOME screen To program events and temperatures perform the follow ing steps once with Cool selected and once with Heat se lected 1 Press and release PROG am 6 00 period A and the 5 consecutive days are displayed am 6 flashes 2 Use the Up Down arrow buttons to select the desired hour press PROG when the desired hour is reached 3 Use the Up Down arrow buttons to select the desired minute press PROG 4 Use the Up Down arrow buttons to select the desired temperature setpoint press PROG Page 5 51M37 SERIES 5 2 5 Repeat steps 2 through 4 for periods B C and D 6 Repeat steps 1 through 5 for the 2 day program NOTE This thermostat will NOT automatically switch from heating to cooling or vice versa operator involve ment is required At the change of seasons or to accomo date abnormal seasonal temperature swings you must manually select to the opposite conditioning Heat or Cool program FAN Controlling the Fan Operation Use the FAN button to select either continuous fan mode or auto fan mode To change from continuous to auto fan mode or vice ver sa press the FAN button Note whether a fan icon in the FAN box is present indicating that the fan is running or not fan not running If continuous fan mode is enabled ON displayed in FAN box see figure 16 the fan will run continuously regard less of whethe
69. g occupancy and because the first program begins later a less demanding time schedule 5 2 Program Example 5 DAY PROGRAM A D 72 68 64 MID 6AM NIGHT 2 DAY PROGRAM D 72 68 ia 64 6AM NOON 6PM MID NIGHT Figure 12 NOTE Pressing ENTER during the following program ming steps saves and exits to the HOME screen To program events and temperatures perform the follow ing steps once with Cool selected and once with Heat se lected 1 Press and release PROG am 6 00 period A and the 5 consecutive days are displayed am 6 flashes 2 Use the Up Down arrow buttons to select the desired hour press PROG when the desired hour is reached 3 Use the Up Down arrow buttons to select the desired minute press PROG 4 Use the Up Down arrow buttons to select the desired temperature setpoint press PROG 5 Repeat steps 2 through 4 for periods B C and D 6 Repeat steps 1 through 5 for the 2 day program Page 4 505049M 5 1 05 NOTE This thermostat will NOT automatically switch from heating to cooling or vice versa operator involve ment is required At the change of seasons or to accomo date abnormal seasonal temperature swings you must manually select to the opposite conditioning Heat or Cool program FAN Controlling the Fan Operation Use the FAN button to select either continuous fan mode or auto fan mode To change from continuous to auto
70. g resolution 1 F 1 C Page 8 505050M 5 1 05 Smart Setback Recovery via DIP switch 6 Smart Setback Recovery SSR affects the way the ther mostat responds to program events If SSR is disabled the thermostat will react to a program event at the time the event occurs However if SSR is enabled the thermostat will react to a program event before the event occurs such that the desired temperature is reached at the time of the event not after Fan Control AUTO or ON modes 1 0 Relays All thermostat relays are latching type to minimize power consumption Table 4 51M37 Terminal Designations Description Reversing valve heat active Reversing valve cool active 24VAC First stage cooling heating compressor energized Auxiliary heating furnace energized Second stage cooling heating compressor energized Emergency heat Fan control Service Indicator 24VAC common Outdoor temperature sensor connection 1 Outdoor temperature sensor connection 2 For most applications E will be jumpered to W1 If sep arate wires are not provided for both E and W1 jumper the E terminal to the W1 terminal on the thermostat sub base For applications involving the use of a balance point whereby the outdoor temperature is to be used to restrict either heat pump operation or backup heat source operation the optional outdoor sensor part number X2658 MUST be installed Equipment Pro
71. ge then while the top is in place pivot the bottom toward the wall until the thermostat snaps into place Default Thermostat Settings Default thermostat settings are in table 2 and the default program is shown in table 3 Table 2 Default Thermostat Settings Mode Heat Permanent Hold Mode Setpoint 70 F or 21 C Fan Auto Filter Reminder OFF Maintenance Reminder OFF Equipment Protection Reset Back to Zero Timers Table 3 Default Program Settings Programs Weekday A Time Temperature Heat 70 F 21 C Temperature Cool 78 F 26 C Weekday B 62 F 17 C 85 F 29 C Weekday C 70 F 21 C 78 F 26 C Weekday D Weekend A 62 F 17 C 70 F 21 C 82 F 28 C 78 F 26 C Weekend B 62 F 17 C 85 F 29 C Weekend C 70 F 21 C 78 F 26 C Weekend D 62 F 17 C 82 F 28 C Monday Tuesday Wednesday Thursday Friday Page 6 505049M 5 1 05 Saturday Sunday Technical Specifications Thermostat Type Electronic programmable thermostat for 2 Stage gas or electric Heat 2 Stage Cool non heat pump non power robbing applications Power Supply Range 18VAC 30VAC 24VAC nominal 60Hz 4 CAUTION 24VAC is present on the terminals of the thermostat bracket If removing the thermostat from the wall use caution and avoid touching any of the connec
72. gram event at the time the event occurs However if SSR is enabled the thermostat will react to a program event before the event occurs such that the desired temperature is reached at the time of the event not after Fan Control AUTO or ON modes gas or electric heat compatible via DIP switches also see Thermostat Output section O Relays All thermostat relays are latching type to minimize power consumption Table 4 51M35 Terminal Designations Description 24VAC First stage cooling First stage heating Second stage heating Fan control Service Indicator 24VAC common Ro Second stage cooling Equipment Protection Timers Minimum Compressor OFF time 5 minutes Minimum Compressor ON time 4 minutes Minimum Furnace ON time 3 minutes Minimum furnace cycle time elapsed time between any furnace activation and the next furnace activation 6 min utes Minimum elapsed time between any compressor activa tion and the next compressor activation 6 minutes NOTE All protection timers except the compressor OFF timer can be over ridden if a heating or cooling demand is initiated or terminated using the UP DOWN HEAT or COOL buttons Equipment Protection Override Both the minimum compressor OFF timer and the mini mum equipment cycle timer can be over ridden by press ing and holding either the HEAT or COOL button down for 4 seconds Over Temperature Protection Thermal mechanical switch opens W1 and W2 at 93 F
73. h ing expecting another input Start making changes within 15 seconds or the HOME screen will return Thermostat Buttons Heat Cool QOQ Prog Day Time OQO Fan Hold OO Settings Enter OO Figure 3 When an Arrow HOLD HEAT or COOL button is pressed SETPOINT and the temperature setting appears for 15 seconds If desired start making changes within 15 sec onds or the HOME screen will return The backlight will turn off 15 seconds after the HOME screen reappears DAY TIME Setting the Day and Time Press the DAY TIME button and set the CURRENT hour minute and day of week as follows 1 am12 will flash on the screen Press the UP DOWN arrows to change the hour AM or PM must corre spond to time of day Press DAY TIME OR if adjust ing for daylight savings time pressing ENTER stores the single change and exits to the HOME screen by passing minutes and day of week 2 Minutes will flash Use the UP DOWN arrow button to display the minutes past the hour Press DAY TIME 3 Day MO Monday will flash Use UP or DOWN arrow buttons to display the current day Day selections are abbreviated as MO TU WE TH FR SA and SU Press DAY TIME 4 The HOME screen reappears confirm day and time are correct This completes day and time setting Page 2 505049M 5 1 05 H
74. he RESET button is pressed ALL settings re vert back to the defaults including the default pro gram see tables 2 and 3 The RESET button is an unlabeled recessed button lo cated behind the door on the right hand side of the thermo stat below the SETTINGS button see figure 3 Use a pa per clip or small pencil to press the RESET button ALL thermostat settings will be reset to the defaults listed in the Default Thermostat Settings section Page 6 505068M 07 05 Removing and Installing Thermostat The thermostat hinges on tabs on the top of the subbase no tool is needed to remove the thermostat from the sub base Pivot the bottom of the thermostat outward releas ing the snaps then lift up to remove To install it first position the top tilted toward the wall brack et and align it until you feel the tabs and slots engage then while the top is in place pivot the bottom toward the wall until the thermostat snaps into place Default Thermostat Settings Default thermostat settings are in table 2 and the default program is shown in table 3 Table 2 Default Thermostat Settings Mode Heat Perm Hold Table 4 Thermostat Outputs Condition W2 Y1 Gas Heat Auto Fan Heat Demand SMALL Heat Demand LARGE Cool Demand SMALL Cool Demand LARGE No Demand Gas Heat Continuous Fan Heat Demand SMALL X Heat Demand LARGE X Cool Demand SMALL Cool Demand LARGE No Demand Electric Heat Auto Fan Heat Demand
75. ialization 505 048M Within a few seconds the Home Screen appears see fig ure 2 with default settings as shown After about 1 minute of initialization time the actual room temperature will be displayed Home Screen MO ee on AM a __ __ De vs vs FAN HOLD AUTO SYSTEM ROOM o r us HEAT Figure 2 At this point the thermostat will be fully functional its de fault temperature setpoint not shown is 70 F At this point if the equipment has been fully powered and if a heat demand were present the system would begin operating NOTE Temperature scale default is Fahrenheit units but may be reset to show Celsius if desired See page 7 Buttons Backlight Timers amp Settings Buttons are located behind the small door on the right hand side of the thermostat see figure 3 A IMPORTANT Do NOT begin pressing buttons until after you read the following section describing each button A pale blue display backlight illuminates for 30 seconds each time any button is pressed When PROG or DAY TIME is pressed a field begins flash ing expecting another input Start making changes within 15 seconds or the HOME screen will return Thermostat Buttons Heat Cool O Prog Day Time OOQ Fan Hold OQ Settings Enter OO Figure 3 When an Arrow HOLD HEAT or COOL button is pressed SETPOINT
76. ime has elapsed a FILTER indicator is displayed Maintenance Reminder Settings of Off 6 or 12 months of chronological time are available When programmed time has elapsed a mainte nance indicator MAINTENANCE is displayed Service Reminder The SERVICE indicator is displayed only under the follow ing conditions e if the thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the R terminal OR e if the thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the C terminal Power Loss Recovery Thermostat memory is retained for a minimum of 24 hours during a power loss includes retention of clock setting program information HOLD status programmed temper ature setpoint heat cool and fan mode settings filter re minder status maintenance reminder status and equip ment protection timers After 24 hours of power loss programmed settings will be lost and replaced with default settings A IMPORTANT Power must be applied for at least six consecutive hours prior to a power loss in order for memory to be retained for the specified time LCD Backlight Activated for 30 seconds when any button is pressed NOTE During an electrical storm or similar disturbance the backlight may activate for a few seconds This is nor mal and will no longer occur after the electrical disturbance has passed Therm
77. in 15 sec onds or the HOME screen will return The backlight will turn off 15 seconds after the HOME screen reappears DAY TIME Setting the Day and Time Press the DAY TIME button and set the CURRENT hour minute and day of week as follows 1 am12 will flash on the screen Press the Up Down ar rows buttons to change the hour AM or PM must correspond to time of day Press DAY TIME OR if ad justing for daylight savings time pressing ENTER stores the single change and exits to the HOME screen bypassing minutes and day of week 2 Minutes will flash Use the Up Down arrow buttons to display the minutes past the hour Press DAY TIME 3 Day MO Monday will flash Use Up Down arrow buttons to display the current day Day selections are abbreviated as MO TU WE TH FR SA and SU Press DAY TIME 4 The HOME screen reappears confirm day and time are correct This completes day and time setting Page 2 505050M 5 1 05 HEAT Using the Heat Mode Normal Heat Mode In normal heat mode both the heat pump and the backup heat source are used to provide heat If the thermostat de tects that the heat pump is not able to provide enough heat as may be the case in very cold weather then the backup heat source is activated Emergency Heat Mode In emergency heat mode only the backup heat source provides heat the heat pump is disabled The backup heat sou
78. is indicates that the equipment requires service from a qualified service technician MO Se ae Service Indicator Flashing MnO ss AM OS rn PROG E AUTO ROOM SYSTEM Wz D 0 it HEAT Figure 21 Thermostat RESET Under some abnormal conditions it may be necessary to reset the thermostat to its default condition Such a RE SET would delete all programming and settings and there fore should only be used on rare occasions when the the thermostat fails to function as designd and or as pro grammed Such an instance can occur as a result of a pow er surge or similar electrical disturbance e g after an elec trical storm or power outage The RESET button can be used to recover from this situation 4 CAUTION When the RESET button is pressed ALL settings re vert back to the defaults including the default pro gram see tables 2 and 3 The RESET button is an unlabeled recessed button lo cated behind the door on the right hand side of the ther mostat below the SETTINGS button see figure 3 Use a paper clip or small pencil to press the RESET button ALL thermostat settings will be reset to the defaults listed in the Default Thermostat Settings section Removing Installing Thermostat The thermostat hinges on tabs on the top of the subbase no tool is needed to remove the thermostat from the sub base Pivot the bottom of the thermostat outward releas ing the snaps then lift up to rem
79. l ook Copy from MO Prog Auto o a Copy Day Time eo M Fan Hold Settings Enter cr outside O Figure 12 7 Repeat steps 1 5 to program different times and tem peratures for days not yet programmed FAN Controlling the Fan Operation Use the FAN button to select either continuous fan mode or auto fan mode To change from continuous to auto fan mode or vice ver sa press the FAN button Note whether a fan icon in the FAN box is present indicating that the fan is running or not fan not running If continuous fan mode is enabled ON displayed in FAN box see figure 13 the fan will run continuously regard less of whether the heating or cooling equipment is run ning Using Fan ON Heat cool Prog Auto Copy Day Time Fan Hold o Figure 13 If auto fan mode is selected AUTO displayed in FAN box see figure 14 the fan will only run when the heating or cooling equipment is running Using Fan AUTO Heat cool Prog Auto Copy Day Time Fan Hold o Figure 14 Page 5 51M39 SERIES 5 2 Displaying Outside Temperature Pressing the ENTER Outside button at the HOME screen displays the outside temperature see figure 15 for several seconds then returns to room temperature Check Outside Temperature a we Fan 4 A L Settings Enter p X
80. ling equipment has been turned off NOTE If no buttons are pressed during a demand for cooling the equipment must operate for at least 4 minutes After a demand has been satisfied cooling equipment op eration is locked out for 5 minutes If another cooling de mand occurs during this 5 minute interval COOL and the snowflakes will flash however the cooling equipment will not operate until the 5 minute delay has elapsed NOTE The cooling setpoint cannot be lower than the heating setpoint Also the difference between the cooling and heating setpoint must be at least 4 degrees AUTO Using the Autochangeover Mode When in either heat mode or cool mode autochangeover can be enabled or disabled by pressing the AUTO button If enabled AUTO appears at the lower right corner of the dis play The thermostat will then automatically change over from heating to cooling and vice versa to keep the room temperature in between the heating and cooling setpoints Autochangeover can be used in either of the thermostat hold modes or when the thermostat program is running These modes are described later Page 3 51M38 SERIES 5 2 HOLD Using Temperature Hold Modes When HOLD is displayed at the HOME screen the ther mostat is in a temperature hold condition This means that the temperature program data is ignored and the thermo stat functions much like a non programmable thermostat Adjusting Temperature Setpoint in Hold Mode
81. ll days D Thermostat Output Table Table 4 depicts the 51M42 thermostat output states for var ious input conditions The following notes described terms used in the table NOTES e X output is activated with 24VAC BBP outdoor temperature is below balance point e ABP outdoor temperature is above balance point e In all cases the state of the B terminal is opposite that of the O terminal Data are tabulated for AUTO fan setting If the fan set ting is ON the G output is activated in all cases Upstage timers 30 minutes when upstaging from small to large demand 15 minutes HEAT MODE ONLY when upstaging from large to very large demand The temperature ranges expressed in the following definitions of SMALL LARGE VERY LARGE de mands are for guidance only actual temperatures may vary With a SMALL heat demand temperature is below setpoint 0 5F but above setpoint 1 5F AND 30 minute upstage timer HAS NOT expired With a LARGE heat demand temperature is less than setpoint 1 5F OR 30 minute upstage timer HAS expired Page 8 505069M 07 05 LARGE X VERY LARGE X Emergency X No Demand With Gas Backup dual fuel no outdoor se SMALL X LARGE X VERY LARGE Emergency X No Demand With Electric Backup outdoor sensor attached SMALL Above Balance Point X LARGE ABP VERY LARGE ABP SMALL Below
82. ll protection timers except the compressor OFF timer can be over ridden if a heating or cooling demand is initiated or terminated using the UP DOWN HEAT or COOL buttons Equipment Protection Override Both the minimum compressor OFF timer and the mini mum equipment cycle timer can be over ridden by press ing and holding either the HEAT or COOL button down for 4 seconds Over Temperature Protection Thermal mechanical switch opens W1 Y1 Y2 and E at 93 F 6 F Filter Reminder Settings of Off 1 3 6 or 12 months of fan run time are available When programmed time has elapsed a FILTER indicator is displayed Maintenance Reminder Settings of Off 6 or 12 months of chronological time are available When programmed time has elapsed a mainte nance indicator MAINTENANCE is displayed Service Reminder The SERVICE indicator is displayed only under the follow ing conditions e ifthe thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the R terminal OR e ifthe thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the C terminal Power Loss Recovery Thermostat memory is retained for a minimum of 24 hours during a power loss includes retention of clock setting program information HOLD status programmed temper ature setpoint heat cool and fan mode settings filter re minder status maint
83. ls being delivered during a demand If a small heat pump heating demand is present Lo is dis played in the SYSTEM box if a large heat pump heating demand is present Hi is displayed see figure 8 Large Heat Heating Demand ROOM a uy HEAT SETPOINT w w o HEAT 4 ad vs 6 om D Figure 8 Page 3 51M42 SERIES 5 2 COOL Using the Cool Mode Enabling and Disabling Cool Mode Use the COOL button to enable or disable cool mode as desired If the thermostat is in heat or off mode cool mode is enabled when the COOL button is pressed This is indi cated by COOL on the right side of the display see figure 9 Turn Cool ON OFF Heat Cool o Prog Auto wo ook mo CMa mae aM ia HoD UNS OOS re s us Cr HEAT SETPOINT gt Settings Enter cr D gt a F Outside Figure 9 If the thermostat is in cool mode pressing the COOL but ton disables cool mode indicated by OFF on the right side of the display Cooling Demand Set the thermostat to cool mode to control the cooling equipment Then if the room temperature is higher than the temperature setpoint as shown in figure 10 the ther mostat detects a cooling demand and will activate the cool ing equipment to satisfy the demand Cooling Demand COOL SETPOINT n v o Ww a Pact Pe a C o HEAT SETPOINT a a o D Dal vets Figure 10
84. ment has been turned off If your system supports 2 stage heating as does the 51M35 thermostat you may notice various heating levels being delivered during a demand NOTE Heating equipment is activated for at least 3 min utes if no buttons are pressed during the demand interval COOL Using the Cool Mode Enabling and Disabling Cool Mode Use the COOL button to enable or disable cool mode as desired If the thermostat is in HEAT or OFF mode cool mode is enabled when the COOL button is pressed This is indicated by COOL in the SYSTEM box see figure 8 Turn Cool ON OFF Heat S Prog Day Time MO AM OFA a TANA ja ON a A vy HOLD auTo a OQ SETPOINT COOL Hold OQ Settings Enter OQO ROOM 1 ree ee ca ous E Figure 7 If the thermostat is in cool mode pressing the Cool button disables COOL mode indicated by OFF in the SYSTEM box see figure 5 Cooling Demand Set the thermostat to cool mode to control the cooling equipment Then if the room temperature is higher than the temperature setpoint as shown in figure 8 the thermo stat detects a cooling demand and will activate the cooling equipment to satisfy the demand Cooling Demand SYSTEM COOL ak ROOM SETPOINT NE Ga igure amp Cooling operation is indicated by flashing snowflake icons in the SYSTEM box When the actual temperatu
85. ment requires service from a qualified service technician Thermostat RESET Under some abnormal conditions it may be necessary to reset the thermostat to its default condition Such a RE SET would delete all programming and settings and there fore should only be used on rare occasions when the the thermostat fails to function as designed and or as pro grammed Such an instance can occur as a result of a pow er surge or similar electrical disturbance e g after an elec trical storm or power outage The RESET button can be used to recover from this situation 4 CAUTION When the RESET button is pressed ALL settings re vert back to the defaults including the default pro gram see tables 2 and 3 The RESET button is an unlabeled recessed button lo cated behind the door on the right hand side of the ther mostat below the SETTINGS button see figure 3 Use a paper clip or small pencil to press the RESET button ALL thermostat settings will be reset to the defaults listed in the Default Thermostat Settings section Removing Installing Thermostat The thermostat hinges on tabs on the top of the subbase no tool is needed to remove the thermostat from the sub base Pivot the bottom of the thermostat outward releas ing the snaps then lift up to remove To replace it first position the top tilted toward the wall bracket and align it until you feel the tabs and slots engage then while the top is in place pivo
86. month reminder displays in 2 calendar months Elapsed chronological time in months Off 6 12 Use this for example to remind yourself when to perform routine checks or when to call a technician for perodic preventive maintenance Enter Stores settings NOTE The HOME screen will reappear about 15 seconds after the final arrow button press OR press the ENTER button at any time to store any changes and exit to the HOME screen After either programmed interval has elapsed the remind er will be displayed as shown in figure 19 Page 6 505069M 07 05 Reminders MO T 4D v am 0 aA Filter amp Maintenance Indicators FILTER MAINTENANCE ROOM Wy wo lt A us FAN autan l KaMe ROOM w gt Service Indicator Flashing Figure 19 After the filter has been changed or maintenance per formed reset the reminder by pressing the SETTINGS button for 4 seconds at the corresponding reminder set tings screen The screen will blink for a few moments to in dicate that the timer has been reset SETTINGS Balance Point NOTE The balance point is only available with the out door sensor When the outdoor sensor X2658 is connected to the 51M42 thermostat balance point adjustment is available The balance point feature allows the measured outdoor temperature to govern operation of the heat pump and backup heat source Press the SETTINGS button thre
87. nowflakes will flash however the cooling equipment will not operate until the 5 minute delay has elapsed Page 3 51M34 SERIES 5 2 HOLD Using Temperature Hold Modes When HOLD is displayed at the HOME screen the ther mostat is in a temperature hold condition This means that the temperature program data is ignored and the thermo stat functions much like a non programmable thermostat Adjusting Temperature Setpoint in Hold Mode The temperature setpoint represents the desired tempera ture of the space around the thermostat The default tem perature setpoint in Hold mode is 70 F To adjust the setpoint press the UP or DOWN A V arrow buttons see figure 9 the existing setpoint is displayed to the right of the actual room temperature Each button press adjusts the setpoint up or down by 1 degree Hold Temperature Mode Heat Cool MO AM Oha 36 nn 8 6 2 O pe ws Prog Day Time rs AUTO R EM a SETPOINT cool Fan Hold ic oo OC Settings Enter OO Figure 9 After the desired setpoint is reached the HOME screen will reappear after about 15 seconds Permanent Hold Mode At any time the program is running from the HOME screen set a permanent hold program override by press ing the HOLD button see figure 9 The thermostat now functions much like a non programmable thermostat Use the Up Down arrow buttons to adjust the hold setpoint To return to the program press HOLD again Tem
88. o remind you when the filter needs changing or when routine maintenance is re quired as and if defined by you These optional remind ers are not enabled until you activate them To do so press the Settings button shown below the Fan button in figure 14 once or twice for the desired reminder as shown in fig ure 15 and as described in table 1 Reminder Settings Display Buttons to Use Settings 1st press then Arrows to scroll selections Settings 2nd press then Arrows to scroll selections For MAINT MAINT press Settings T button 2 times For FILTER press Settings button 1 time Figure 15 The default setting for the reminders is OFF disabled Press Up Down arrow buttons to select the desired re minder intervals Table 1 Filter and Maintenance Reminders Reminder FILTER Available Settings and How to Use Total fan run time expressed in months Off 1 3 6 12 for example if fan runs 12 hours a day 1 month reminder displays in 2 calendar months Elapsed chronological time in months Off 6 12 Use this for example to remind yourself when to perform routine checks or when to call a technician for perodic preventive maintenance Stores settings Enter NOTE The HOME screen will reappear about 15 seconds after the final arrow button press OR press ENTER at any time to store any changes and exit to the HOME screen After either programmed
89. on time the actual room temperature will be displayed NOTE Tables 2 and 3 on page 8 show all system and programming defaults Home Screen MO en on AM D E q De a vs vs FAN HOLD AUTO SYSTEM ROOM o aia us HEAT Figure 2 At this point the thermostat will be fully functional its de fault temperature setpoint not shown is 70 F At this point if the equipment has been fully powered and if a heat demand were present the system would begin operating NOTE Temperature scale default is Fahrenheit units but may be reset to show Celsius if desired See page 8 Buttons Backlight Timers amp Settings Buttons are located behind the small door on the right hand side of the thermostat see figure 3 A IMPORTANT Do NOT begin pressing buttons until after you read the following section describing each button A pale blue display backlight illuminates for 30 seconds each time any button is pressed When PROG or DAY TIME is pressed a field begins flash ing expecting another input Start making changes within 15 seconds or the HOME screen will return Thermostat Buttons Heat Cool O Prog Day Time OOQ Fan Hold OQ Settings Enter OO Figure 3 When an Arrow HOLD HEAT or COOL button is pressed SETPOINT and the temperature setting appears for 15 seconds If desired start making changes with
90. ostat Operating Conditions 35 F to 105 F 5 to 90 RH Thermostat Storage Conditions 40 F to 185 F 5 to 95 RH Page 9 51M39 SERIES 5 2 LENNOX J 2005 Lennox Industries Inc Dallas Texas USA MO TU WE TH FR SA SU PROG DEGE AM it HOLD PM 0 Mafa FAN COOL SETPOINT AUTO re o LENNOX D RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE 51M42 Merit Series Thermostat The Lennox Merit Series 7 day programmable electronic thermostat 51M42 provides excellent temperature control and a large easy to read display It includes a programmable filter change reminder an equipment maintenance reminder and a system check indicator to notify the user when the equipment requires service Thermostat 51M42 is suitable for heat pump three stage heat two stage cool applications using a gas or electric auxiliary heat source In addition to displaying outdoor temperature the outdoor temperature sensor provides auxiliary heat lockout balance point operation and dual fuel compatibility Also the thermostat provides auto changeover capability These instructions are intended as a general guide and do not supersede local codes in any way Consult authorities having jurisdiction before installation Check equipment for shipping damage If you find any damage immediately contact the last carrier Introduction This document describes the operation of Lennox thermostat 51M42 Refer to the installation manual for ins
91. ove To replace it first position the top tilted toward the wall bracket and align it until you feel the tabs and slots engage then while the top is in place pivot the bottom toward the wall until the thermostat snaps into place Page 7 51M37 SERIES 5 2 Default Thermostat Settings Default thermostat settings are shown in table 2 and the default program is shown in table 3 Table 2 Default Thermostat Settings Mode Mode Heat Permanent Hold Setpoint 70 F or 21 C Fan Auto Filter Reminder OFF Maintenance Reminder OFF Equipment Protection Timers Table 3 Reset Back to Zero Default Program Settings Programs Time Weekday A Temperature Heat 70 F 21 C Temperature Cool 78 F 26 C Weekday B 62 F 17 C 85 F 29 C Weekday C 70 F 21 C 78 F 26 C Weekday D Weekend A 62 F 17 C 70 F 21 C 82 F 28 C 78 F 26 C Weekend B 62 F 17 C 85 F 29 C Weekend C 70 F 21 C 78 F 26 C Weekend D 62 F 17 C 82 F 28 C Monday Tuesday Wednesday Thursday Friday Saturday Sunday Technical Specifications Thermostat Type Electronic programmable thermostat for heat pump 3 stage heat 2 stage cool NOTE 2 stages of heat pump heat and one stage of auxil iary gas or electric backup heat are supported Pow
92. pale blue display backlight illuminates for 30 seconds each time any button is pressed When the PROG or DAY TIME button is pressed a field begins flashing expecting another input Start making changes within 15 seconds or the HOME screen will re turn Thermostat Buttons Heat Cool T V Prog Auto a amp wo ook Fan Hold a amp wv Settings Enter m 5 Outside Figure 3 When an Arrow HOLD HEAT or COOL button is pressed SETPOINT and the temperature setting appears for 15 seconds If desired start making changes within 15 sec onds or the HOME screen will return The backlight will turn off 15 seconds after the HOME screen reappears DAY TIME Setting the Day and Time Press the DAY TIME button and set the CURRENT hour minute and day of week as follows 1 am12 will flash on the screen Press the UP DOWN arrows to change the hour AM or PM must corre spond to time of day Press the DAY TIME button OR if adjusting for daylight savings time pressing the EN TER button stores the single change and exits to the HOME screen bypassing minutes and day of week 2 Minutes will flash Use the UP DOWN arrow button to display the minutes past the hour Press the DAY TIME button 3 Day MO Monday will flash Use UP or DOWN arrow buttons to display the current day Day selections are abbreviated as MO TU WE TH
93. porary 2 Hour Hold At any time the program is running from the HOME screen set a temporary 2 hour hold by pressing the Up Down arrow buttons until the desired setpoint is displayed HOLD flashes see figure 10 This overrides the pro gram for 2 hours from the last button press then returns to the program Temporary Hold Temperature Mode MO AM PTE ea rp ae Proc E gt Foun Auro 77 N SYSTEM ROOM eg S QQ Prog Day Time a ia be D xx a Vt Da Settings Enter OO Figure 10 While in Temporary Hold press HOLD once to switch to Permanent Hold HOLD displays solid PROG not dis played press HOLD again to return to the program PROG displays HOLD not displayed PROG Thermostat Programming The 51M34 thermostat can be programmed to perform a set of either heating or cooling events but not a combination of heat and cool for 5 consecutive days using a set of 4 unique events per day The remaining 2 days can then be set for a different set of 4 unique events per day Both the consecutive days and the events temperature are set by the homeowner To Change Consecutive Days To alter the 5 consecutive days press and hold the PROG button for 5 seconds The existing 5 consecutive day peri od is then displayed default is MOnday thru FRiday To change to a different 5 consecutive days use the Up Down arrow buttons Any 5 consecutive day span may be selected for exampl
94. r Copy from MO with MO flashing Press the COPY button again to copy Monday s program B The display changes to Copy to MO Use the ar row buttons to scroll to the desired day where you want the same program as Monday Press the COPY button C Repeat steps A and B for as many days as you want the same program 7 Copy a Programmed Day to Another Day Heat Cool Copy from MO TF Prog Auto o Copy Day Time M Fan Hold O Settings Enter cr 6 Outside Figure 14 7 Repeat steps 1 5 to program different times and tem peratures for days not yet programmed 51M42 SERIES 5 2 FAN Controlling the Fan Operation Use the FAN button to select either continuous fan mode or auto fan mode To change from continuous to auto fan mode or vice ver sa press the FAN button Note whether a fan icon in the FAN box is present indicating that the fan is running or not fan not running If continuous fan mode is enabled ON displayed in FAN box see figure 15 the fan will run continuously regard less of whether the heating or cooling equipment is run ning Using Fan ON Cool Auto A K Copy Day Time a a o F Fan Hold amp wa Figure 15 If auto fan mode is selected AUTO displayed in FAN box see figure 16 the fan will only run when the heating or cooling equipment is running Using Fan AUTO Copy Day Tim
95. r DOWN A V arrow buttons see figure 9 the existing setpoint is displayed to the right of the actual room temperature Each button press adjusts the setpoint up or down by 1 degree Hold Temperature Mode Heat Cool MO AM Oha 36 nn 8 6 2 O pe ws Prog Day Time rs AUTO R EM a SETPOINT cool Fan Hold ic oo OC Settings Enter OO Figure 9 After the desired setpoint is reached the HOME screen will reappear after about 15 seconds Permanent Hold Mode At any time the program is running from the HOME screen set a permanent hold program override by press ing the HOLD button see figure 9 The thermostat now functions much like a non programmable thermostat Use the Up Down arrow buttons to adjust the hold setpoint To return to the program press HOLD again Temporary 2 Hour Hold At any time the program is running from the HOME screen set a temporary 2 hour hold by pressing the Up Down arrow buttons until the desired setpoint is displayed HOLD flashes see figure 10 This overrides the pro gram for 2 hours from the last button press then returns to the program Temporary Hold Temperature Mode MO AM PTE ea rp ae Proc E gt Foun Auro 77 N SYSTEM ROOM eg S QQ Prog Day Time a ia be D xx a Vt Da Settings Enter OO Figure 10 While in Temporary Hold press HOLD once to switch to Permanent Hold HOLD displays solid PROG
96. r the heating or cooling equipment is run ning Using Fan ON Heat Cool QQ Prog Day Time OC Fan Hold JO Settings Enter ODO Figure 16 If auto fan mode is selected AUTO displayed in FAN box see figure 17 the fan will only run when the heating or cooling equipment is running Using Fan Auto Heat Cool AM 50 Sa Fa Se i 2 e EPP Ln Prog Day Time PROG E AUTO O O ROOM oor p kx Fan Hold Ok pe O MO Settings Enter OO Figure 17 SETTINGS Filter Maintenance Reminders The 51M37 thermostat is designed to remind you when the filter needs changing or when routine maintenance is re quired as and if defined by you These optional remind ers are not enabled until you activate them To do so press the Settings button shown below the Fan button in figure 17 once or twice for the desired reminder as shown in fig ure 18 and as described in table 1 Reminder Settings Display Buttons to Use Settings 1st press then Arrows to scroll selections Settings 2nd press then Arrows to scroll selections _ For MAINT MAINT press Settings TE button 2 times For FILTER press Settings button 1 time Figure 18 The default setting for the reminders is OFF disabled Press Up Down arrow buttons to select the desired re minder intervals Table 1 Filter and Maintenance Reminders Reminder FILTER Available Settings
97. rature Measurement Range Measurement Scale Fahrenheit Measurement Range 35 F to 99 F Measurement Resolution 0 5 F Measurement Accuracy 1 F Field Offset via DIP switches to 3 F Sampling Method temperature measurements sampled every 15 seconds Displayed temperature is the average of the last four measurements Temperature Setpoint Range Setting range 50 F 10 C to 90 F 32 C Setting resolution 1 F 1 C Smart Setback Recovery via DIP switch 6 Smart Setback Recovery SSR affects the way the ther mostat responds to program events If SSR is disabled the thermostat will react to a program event at the time the event occurs However if SSR is enabled the thermostat will react to a program event before the event occurs such that the desired temperature is reached at the time of the event not after Fan Control AUTO or ON modes gas or electric heat compatible via DIP switches also see Thermostat Output section 1 0 Relays All thermostat relays are latching type to minimize power consumption Table 4 51M34 Terminal Designations Description 24VAC First stage cooling Terminal First stage heating Fan control Service Indicator 24VAC common Equipment Protection Timers Minimum Compressor OFF time 5 minutes Minimum Compressor ON time 4 minutes Minimum Furnace ON time 3 minutes Minimum furnace cycle time elapsed time between any furnace activation and the n
98. rce is activated only when there is a heat demand Enabling Normal Heat Mode Use the HEAT button to select normal heat mode emer gency heat mode or to disable heat modes as desired If the thermostat is in OFF or COOL mode pressing the Heat button enables Heat mode This is indicated by HEAT in the SYSTEM box as shown in figure 4 Normal Heat Mode Enabled MO A AM Ka tan a abn NS HOLD auto Day Time SYSTEM ROOM SETPOINT mee ne Hear Hold OQ Settings Enter Figure 4 Enabling Emergency Heat Mode If the thermostat is in heat mode pressing the Heat button enables EMG HEAT mode see figure 5 If the thermostat is in normal heat mode when the HEAT button is pressed then emergency heat mode is enabled Emergency Heat Mode Enabled ROOM SETPOINT lt gt lt ag g a bat ae 2 Figure 5 Disabling Heat Mode If the thermostat is in emergency heat mode when the HEAT button is pressed then heat modes are disabled This is indicated by OFF in the SYSTEM box as shown in figure 6 ay ap Heat Mode Disabled SYSTEM ROOM w x SETPOINT q md 40 OFF Figure 6 Heating Demand The thermostat must be in either normal or emergency heat mode in order to properly control the heating equip ment In either heat mode when the actual temperature is lower than the temperature setpoint as shown in figur
99. re drops below the temperature setpoint the snowflake icons will disappear This indicates that the cooling demand has been satisfied and that the cooling equipment has been turned off If your system supports 2 stage cooling as does the 51M35 thermostat you may notice various cooling levels being delivered during a demand Also if a small cooling demand is present Lo will be displayed in the SYSTEM box However if a large cooling demand is present Hi will be displayed in the SYSTEM box shown in figure 8 NOTE If no buttons are pressed during a demand for cooling the equipment must operate for at least 4 minutes After a demand has been satisfied cooling equipment op eration is locked out for 5 minutes If another cooling de mand occurs during this 5 minute interval COOL and the snowflakes will flash however the cooling equipment will not operate until the 5 minute delay has elapsed Page 3 51M35 SERIES 5 2 HOLD Using Temperature Hold Modes When HOLD is displayed at the HOME screen the ther mostat is in a temperature hold condition This means that the temperature program data is ignored and the thermo stat functions much like a non programmable thermostat Adjusting Temperature Setpoint in Hold Mode The temperature setpoint represents the desired tempera ture of the space around the thermostat The default tem perature setpoint in Hold mode is 70 F To adjust the setpoint press the UP o
100. rminal Data are tabulated for AUTO fan setting If the fan set ting is ON the G output is activated in all cases Upstage timers 30 minutes when upstaging from small to large demand 15 minutes HEAT MODE ONLY when upstaging from large to very large demand The temperature ranges expressed in the following definitions of SMALL LARGE VERY LARGE de mands are for guidance only actual temperatures may vary With a small HEAT demand temperature is below setpoint 0 5F but above setpoint 1 5F AND 30 minute upstage timer HAS NOT expired With a large HEAT demand temperature is less than setpoint 1 5F OR 30 minute upstage timer HAS expired With a very large heat demand temperature is below setpoint 2 5F OR 15 minute 2 upstage timer HAS expired Emergency heat demand only if emergency heat is enabled temperature is below setpoint 0 5F With a small COOL demand temperature is above setpoint 0 5F but below setpoint 1 5F AND 30 minute upstage timer HAS NOT expired With a large COOL demand temperature is above setpoint 1 5F OR 30 minute upstage timer HAS expired Table 5 THERMOSTAT OUTPUTS Demand Condition W1 E Cooling Demands SMALL LARGE No Demand Heating Demands wi Electric Backup no outdoor sensor SMALL X LARGE X Very LARGE X Emergency X No Demand w Gas Backup dual fuel no outdoor sensor
101. s 03 05 Table of Contents 51M37 Series Thermostat 1 General 0 00 000 eee eee eee 1 Introduction 0200 cece eee eee ee 1 Initial Thermostat Power up 005 1 Buttons Backlight Timers amp Settings 2 DAY TIME Set Day and Time 2 HEAT Heat Mode 2 02200005 3 COOL Cool Mode 220202000 0 4 HOLD Temperature Hold Mode 5 PROG Thermostat Programming 5 FAN Controlling Fan Operation 6 SETTINGS Filter and Maintenance Reminders 6 SETTINGS Balance Point 7 Service Indicator 020020e eee eee 7 Thermostat RESET 2 220020e eee 7 Removing Installing Thermostat 7 Default Thermostat Settings 7 Technical Specifications 0 000 ee 8 Thermostat Output Table 10 Initial Power Up Display MO TU WE TH FR SA SU TE m aD AM DnA n 8 Daat PM ON a Dat vs FAN PROGENEJLIDI HOLD ON AUTO SYSTEM L x algae coo Ae Saa e OFF EMG Hi vs Ls HEAT Lo M 0 SETPOINT Figure 1 All display segments are momentarily activated This oc curs as a normal part of thermostat initialization 505 050M Within a few seconds the Home Screen appears see fig ure 2 with default settings as shown After about 1 minute of initializati
102. s Monday Press the COPY button C Repeat steps A and B for as many days as you want the same program Copy a Programmed Day to Another Day Cool Copy from MO a Copy Day Time ww 7 Fan Hold SS o F Settings Enter m a amp wy 5 Outside Figure 11 7 Repeat steps 1 5 to program different times and tem peratures for days not yet programmed FAN Controlling the Fan Operation Use the FAN button to select either continuous fan mode or auto fan mode To change from continuous to auto fan mode or vice ver sa press the FAN button Note whether a fan icon in the FAN box is present indicating that the fan is running or not fan not running If continuous fan mode is enabled ON displayed in FAN box see figure 12 the fan will run continuously regard less of whether the heating or cooling equipment is run ning Using Fan ON Copy Day Time a amp T Y Fan Figure 12 If auto fan mode is selected AUTO displayed in FAN box see figure 13 the fan will only run when the heating or cooling equipment is running Using Fan Auto Heat Cool g Sy d Fan Hold o Figure 13 Displaying Outside Temperature Pressing the ENTER Outside button at the HOME screen displays the outside temperature see figure 14 for several seconds then returns to room temperature Check Outside Temperature
103. s does the 51M37 thermostat you may notice various cooling levels being delivered during a demand Also if a small cooling demand is present Lo will be displayed in the SYSTEM box However if a large cooling demand is present Hi will be displayed in the SYSTEM box shown in figure 11 NOTE If no buttons are pressed during a demand for cooling the equipment must operate for at least 4 minutes After a demand has been satisfied cooling equipment op eration is locked out for 5 minutes If another cooling de mand occurs during this 5 minute interval COOL and the snowflakes will flash however the cooling equipment will not operate until the 5 minute delay has elapsed Page 4 505050M 5 1 05 HOLD Using Temperature Hold Modes When HOLD is displayed at the HOME screen the ther mostat is in a temperature hold condition This means that the temperature program data is ignored and the thermo stat functions much like a non programmable thermostat Adjusting Temperature Setpoint in Hold Mode The temperature setpoint represents the desired tempera ture of the space around the thermostat The default tem perature setpoint in Hold mode is 70 F To adjust the setpoint press the UP or DOWN A V arrow buttons see figure 12 the existing setpoint is displayed to the right of the actual room temperature Each button press adjusts the setpoint up or down by 1 degree Hold Temperature Mode Heat Cool AM wre w
104. shown in Celsius position Figure 18 Display range 35 F 2 C to 99 F 37 C Display resolution 1 F 1 C Display Accuracy 1 F If the Fahrenheit Celsius display must be changed use a plastic non conductive tool to push the dip switch to the right position see figure 18 Indoor Temperature Measurement Range Measurement Scale Fahrenheit Measurement Range 35 F to 99 F Measurement Resolution 0 5 F Measurement Accuracy 1 F Field Offset via DIP switches to 3 F Sampling Method temperature measurements sampled every 15 seconds Displayed temperature is the average of the last four measurements Outdoor Temperature Measurement Range Measurement Scale Fahrenheit Measurement Range 22 F to 122 F Measurement Resolution 1 F Measurement Accuracy 2 F Temperature Setpoint Range Setting range 50 F 10 C to 90 F 32 C Setting resolution 1 F 1 C Smart Setback Recovery via DIP switch 6 Smart Setback Recovery SSR affects the way the ther mostat responds to program events If SSR is disabled the thermostat will react to a program event at the time the event occurs However if SSR is enabled the thermostat will react to a program event before the event occurs such that the desired temperature is reached at the time of the event not after Autochangeover Deadband Selection via DIP switch 7 Autochangeover deadband can be set to 4 or 6 degrees When autochangeover
105. splay Display Scale Fahrenheit or Celsius user selectable via DIP switch see figure 17 Display range 35 F 2 C to 99 F 37 C Display resolution 1 F 1 C Display Accuracy 1 F If the Fahrenheit Celsius display must be changed use a plastic non conductive tool to push the dip switch to the right position see figure 17 Changing Fahrenheit Celsius Setting PLUG IN Use Care To Avoid Bending Prongs F C Fahrenheit Celsius switch shown in Celsius position Figure 17 Indoor Temperature Measurement Range Measurement Scale Fahrenheit Measurement Range 35 F to 99 F Measurement Resolution 0 5 F Measurement Accuracy 1 F Field Offset via DIP switches to 3 F Sampling Method temperature measurements sampled every 15 seconds Displayed temperature is the average of the last four measurements Outdoor Temperature Measurement Range Measurement Scale Fahrenheit Measurement Range 22 F to 122 F Measurement Resolution 1 F Measurement Accuracy 2 F Temperature Setpoint Range Setting range 50 F 10 C to 90 F 32 C Setting resolution 1 F 1 C Page 7 51M38 SERIES 5 2 Smart Setback Recovery via DIP switch 6 Smart Setback Recovery SSR affects the way the ther mostat responds to program events If SSR is disabled the thermostat will react to a program event at the time the event occurs However if SSR is enabled the thermostat will react to a program ev
106. t The default heat setpoint in hold mode is 70 F the default cool setpoint in hold mode is 78 F Hold Temperature Mode Heat Cool ee Prog Auto T V ook mO Je S m UIM Hoan NL OLS aa Cre ro ed us Settings Enter cr By By wy Outside Figure 9 To adjust the setpoint press the UP or DOWN A arrow buttons the existing setpoint is displayed to the right of the actual room temperature Each button press adjusts the setpoint up or down by 1 degree After the desired setpoint is reached the HOME screen will reappear after about 15 seconds Permanent Hold Mode At any time the program is running from the HOME screen set a permanent hold program override by press ing the HOLD button see figure 9 The thermostat now functions much like a non programmable thermostat Use the Up Down arrow buttons to adjust the hold setpoint To return to the program press the HOLD button again Temporary 2 Hour Hold At any time the program is running from the HOME screen set a temporary 2 hour hold by pressing the Up Down arrow buttons until the desired setpoint is displayed HOLD flashes see figure 10 This overrides the pro gram for 2 hours from the last button press then returns to the program While in Temporary Hold press the HOLD button once to switch to Permanent Hold HOLD displays solid PROG not displayed press the HOLD button again to re
107. t the bottom toward the wall until the thermostat snaps into place Page 7 51M42 SERIES 5 2 Default Thermostat Settings Default thermostat settings are shown in table 2 and the default program is shown in table 3 Table 2 Mode Heat Perm Hold 70 F or 21 C 78 F or 26 C Auto OFF OFF Reset Back to Zero OFF Heat Setpoint Perm Hold Cool Setpoint Perm Hold Fan Filter Reminder Maintenance Reminder Equipment Protection Timers Autochangeover With a VERY LARGE heat demand temperature is below setpoint 2 5F OR 15 minute 2 upstage timer HAS expired Emergency heat demand only if emergency heat is enabled temperature is below setpoint 0 5F With a SMALL cool demand temperature is above setpoint 0 5F but below setpoint 1 5F AND 30 minute upstage timer HAS NOT expired With a LARGE cool demand temperature is above setpoint 1 5F OR 30 minute upstage timer HAS expired Table 4 THERMOSTAT OUTPUTS Demand Condition W1 E Cooling Demands Default Program Settings Time amp Temp Programs All days A Time Temp Heat 70 F 21 C Temp Cool 78 F 26 C All days B 62 F 17 C 85 F 29 C All days C 70 F 21 C 78 F 26 C 62 F 17 C 82 F 28 C LARGE No Demand Heating Demands With Electric Backup no outdoor sensor SMALL X A
108. tection Timers Minimum Compressor OFF time 5 minutes Minimum Compressor ON time 4 minutes Minimum Furnace ON time 3 minutes Minimum furnace cycle time elapsed time between any furnace activation and the next furnace activation 6 min utes Minimum elapsed time between any compressor activa tion and the next compressor activation 6 minutes NOTE All protection timers except the compressor OFF timer can be over ridden if a heating or cooling demand is initiated or terminated using the UP DOWN HEAT or COOL buttons Equipment Protection Override Both the minimum compressor OFF timer and the mini mum equipment cycle timer can be over ridden by press ing and holding either the HEAT or COOL button down for 4 seconds Over Temperature Protection Thermal mechanical switch opens W1 Y1 Y2 and E at 93 F 6 F Filter Reminder Settings of Off 1 3 6 or 12 months of fan run time are available When programmed time has elapsed a FILTER indicator is displayed Maintenance Reminder Settings of Off 6 or 12 months of chronological time are available When programmed time has elapsed a mainte nance indicator MAINT is displayed Service Reminder The SERVICE indicator is displayed only under the follow ing conditions e ifthe thermostat Y1 terminal has been activated with 24VAC for at least 5 minutes AND the L terminal is shorted to the R terminal OR e if the thermostat Y1 terminal has been a
109. the lower right corner When the actual temperature rises above the temperature setpoint the flame icon will disappear This indicates that the heating demand has been satisfied and that the heating equipment has been turned off NOTE Heating equipment is activated for at least 3 min utes if no buttons are pressed during the demand interval COOL Using the Cool Mode Enabling and Disabling Cool Mode Use the COOL button to enable or disable cool mode as desired If the thermostat is in heat or off mode cool mode is enabled when the COOL button is pressed This is indi cated by COOL on the right side of the display see figure Turn Cool ON OFF Heat Cool x Prog Auto a a amp wv Fan Hold a amp T V 5 Outside Figure 7 If the thermostat is in cool mode pressing the COOL but ton disables cool mode indicated by OFF similar to figure 5 Cooling Demand Set the thermostat to cool mode to control the cooling equipment Then if the room temperature is higher than the temperature setpoint as shown in figure 7 the thermo stat detects a cooling demand and will activate the cooling equipment to satisfy the demand Cooling operation is indicated by flashing snowflake icons in the display When the actual temperature drops below the temperature setpoint the snowflake icons will disappear This indicates that the cooling demand has been satisfied and that the coo
110. tochangeover can be used in either of the thermostat hold modes or when the thermostat program is running These modes are described later HOLD Using Temperature Hold Modes When the HOLD button is displayed at the HOME screen the thermostat is in a temperature hold condition This means that the temperature program data is ignored and the thermostat functions much like a non programmable thermostat Adjusting Temperature Setpoint in Hold Mode The temperature setpoint represents the desired tempera ture of the space around the thermostat The default heat setpoint in hold mode is 70 F the default cool setpoint in hold mode is 78 F To adjust the setpoint press the UP or DOWN A V arrow buttons see figure 11 the existing setpoint is displayed to the right of the actual room temperature Each button press adjusts the setpoint up or down by 1 degree Hold Temperature Mode Heat Cool O T V Prog Auto we ook Cea Sara wow Ofa INS COOLSETFONT she CX Copy Day Time 0 0 o F Fan Hold a h d Settings Enter r 6 Outside Figure 11 After the desired setpoint is reached the HOME screen will reappear after about 15 seconds Permanent Hold Mode At any time the program is running from the HOME screen set a permanent hold program override by press ing the HOLD button see figure 11 The thermostat now functions much like a non programmable thermostat
111. tructions re garding installation and wiring of the thermostat Initial Thermostat Power up When power is initially applied to the thermostat the dis play will appear as shown in figure 1 07 05 Page 1 OPERATION MANUAL 51M42 Merit Series 7 Day Programmable Thermostat Technical CONTROLS Nees 07 05 Litho U S A Table of Contents 51M42 Series Thermostat 1 General aiis ii aoe aari iar b beens evar ee 1 Introduction ein beside betas Pak bad eee diate 1 Initial Thermostat Power up 0055 1 Buttons Backlight Timers amp Settings 2 DAY TIME Set Day and Time 2 HEAT Heat Mode 2 2200200 20s 3 COOL Cool Mode 020220005 4 AUTO Using the Autochangeover Mode 4 HOLD Temperature Hold Mode 4 PROG Thermostat Programming 5 COPY Copy a Program 2 0 5 FAN Controlling Fan Operation 6 Displaying Outside Temperature 6 SETTINGS Filter and Maintenance Reminders 6 SETTINGS Balance Point 7 Service Indicator 00200 eee eee 7 Thermostat RESET 0200200 eee 7 Removing Installing Thermostat 7 Default Thermostat Settings 7 Technical Specifications 00 00 9 Thermostat Output Table 8 Initial Pow
112. ts The deadband is the minimum difference between the heating and cooling setpoints Fan Control AUTO or ON modes 1 0 Relays All thermostat relays are latching type to minimize power consumption Page 9 51M42 SERIES 5 2 Table 5 51M42 Terminal Designations Description Reversing valve heat active Reversing valve cool active 24VAC First stage cooling heating compressor energized Auxiliary heating furnace energized Second stage cooling heating compressor energized Emergency heat Fan control Service Indicator 24VAC common Outdoor temperature sensor connection 1 Outdoor temperature sensor connection 2 For most applications E will be jumpered to W1 If sep arate wires are not provided for both E and W1 jumper the E terminal to the W1 terminal on the thermostat sub base For applications involving the use of a balance point whereby the outdoor temperature is to be used to restrict either heat pump operation or backup heat source operation the outdoor sensor part number X2658 MUST be installed Equipment Protection Timers Minimum Compressor OFF time 5 minutes Minimum Compressor ON time 4 minutes Minimum Furnace ON time 3 minutes Minimum furnace cycle time elapsed time between any furnace activation and the next furnace activation 6 min utes Minimum elapsed time between any compressor activa tion and the next compressor activation 6 minutes NOTE A
113. tton is pressed This is indicated by COOL in the SYSTEM box see figure 7 Turn Cool ON OFF MO AM CA a TAA jaa cA s 00 Prog Day Time HOLD auTo g y a OO ROOM SETPOINT COOL o w wo amp 4B 1G ay Hold Fan O Settings Enter OO 7 Figure 7 If the thermostat is in cool mode pressing the Cool button disables COOL mode indicated by OFF in the SYSTEM box see figure 5 Cooling Demand Set the thermostat to cool mode to control the cooling equipment Then if the room temperature is higher than the temperature setpoint as shown in figure 8 the thermo stat detects a cooling demand and will activate the cooling equipment to satisfy the demand Cooling Demand SYSTEM COOL x 7 ROOM SETPOINT UE he gt Ara a Cus igure amp Cooling operation is indicated by flashing snowflake icons in the SYSTEM box When the actual temperature drops below the temperature setpoint the snowflake icons will disappear This indicates that the cooling demand has been satisfied and that the cooling equipment has been turned off NOTE If no buttons are pressed during a demand for cooling the equipment must operate for at least 4 minutes After a demand has been satisfied cooling equipment op eration is locked out for 5 minutes If another cooling de mand occurs during this 5 minute interval COOL and the s
114. turn to the program PROG displays HOLD not displayed Temporary Hold Temperature Mode _ Heat Cool A a SE Prog Auto SL a UN a HOD sn N F G00 SETFONT ke H a ROOM im w4 74 neron al mo tE 658 Fan Hold ook AUTO wy Settings Enter cr a amp wv O Outside Figure 10 PROG Thermostat Programming The 51M39 thermostat can be programmed to perform a set of both heating and cooling events for each day of the week Each day can be programmed for 4 unique events per day and each day can be different from any other day To Set Program Events and Temperatures Figure 11 gives an example of how up to 7 different pro grams can be set Programs A and C reflect the desired warmth while the home IS occupied 72 B allows less heating while the home is NOT occupied D reflects a cool sleeping temperature NOTE This example shows heat setpoints a similar pro gram may be set for cool setpoints Page 4 505068M 07 05 Program Example MONDAY PROGRAM 72 68 64 TUESDAY PROGRAM 72 68 64 WEDNESDAY PROGRAM 72 68 64 THURSDAY PROGRAM 72 68 64 FRIDAY PROGRAM 72 68 64 SATURDAY PROGRAM 72 68 64 SUNDAY PROGRAM 72 68 Ay C 64 6AM NOON 6PM MID NIGHT Figure 11 NOTE Pressing the ENTER button
115. vate for a few seconds This is nor mal and will no longer occur after the electrical disturbance has passed Thermostat Operating Conditions 35 F to 105 F 5 to 90 RH Thermostat Storage Conditions 40 F to 185 F 5 to 95 RH Thermostat Output Table Table 5 depicts the 51M35 thermostat output states for var ious input conditions The following notes described terms used in the table NOTE X output is activated with 24VAC NOTE The temperature ranges expressed in the follow ing definitions of SMALL LARGE demands are for guid ance only actual temperatures may vary With a small HEAT demand temperature is below setpoint 0 5F but above setpoint 1 5F AND 30 minute upstage timer HAS NOT expired With a large HEAT demand temperature is less than setpoint 1 5F OR 30 minute upstage timer HAS expired With a small COOL demand temperature is above setpoint 0 5F but below setpoint 1 5F AND 30 minute upstage timer HAS NOT expired With a large COOL demand temperature is above setpoint 1 5F OR 30 minute upstage timer HAS expired Table 5 Thermostat Outputs Condition W2 Y1 Gas Heat Auto Fan HEAT Demand SMALL HEAT Demand LARGE COOL Demand SMALL COOL Demand LARGE No Demand Gas Heat Continuous Fan HEAT Demand SMALL x HEAT Demand LARGE X COOL Demand SMALL COOL Demand LARGE No Demand Electric Heat Auto Fan HEAT Demand SMALL HEAT Demand LARGE COOL Demand SMALL COOL Deman
116. wn After about 1 minute of initialization time the actual room temperature will be displayed NOTE Tables 2 and 3 on page 7 show all system and programming defaults HOME Screen Figure 2 At this point the thermostat will be fully functional its de fault temperature setpoint not shown is 70 F At this point if the equipment has been fully powered and if a heat demand were present the system would begin operating NOTE Temperature scale default is Fahrenheit units but may be reset to show Celsius if desired See page 8 Buttons Backlight Timers amp Settings Buttons are located behind the small door on the right hand side of the thermostat see figure 3 A IMPORTANT Do NOT begin pressing buttons until after you read the following section describing each button A pale blue display backlight illuminates for 30 seconds each time any button is pressed When PROG or DAY TIME button is pressed a field be gins flashing expecting another input Start making changes within 15 seconds or the HOME screen will re turn Thermostat Buttons Heat Cool T V Prog Auto a amp wo ook Fan Hold wo Settings Enter m o Outside Figure 3 When an Arrow HOLD HEAT or COOL button is pressed SETPOINT and the temperature setting appears for 15 seconds If desired start making changes within 15 sec onds or the HOME screen will return The

Lennox International Inc. 51M37 Thermostat User Manual

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