Honeywell Boiler L7224A User's Manual
Contents
1. SWITCH MAKES ON TEMPERATURE FALL BURNER IS ON TO MAINTAIN MINIMUM WATER TEMPERATURE CIRCULATOR IS OFF AN WHEN WATER REACHES LOW LIMIT SETTING THE BURNER SHUTS OFF OR THE CIRCULATOR PUMP STARTS WHEN CALLING FOR HEAT M23364 Fig 7 Setpoints and differentials Anti Short Cycle Feature The Anti Short Cycle feature allows for field selection of a delay time between burner cycles Should a call for heat occur following the end of the previous heat cycle and before the Anti Short Cycle delay time is expired the circulator will be allowed to run but the burner will be held off until the time has elapsed The range of the Anti Short Cycle time is from OFF to five minutes L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS NOTE This feature is blocked if a Domestic Hot Water demand occurs Domestic Hot Water demands are serviced immediately without any delay NOTE When the Aquastat is connected to the oil primary and or thermostat via the EnviraCOM bus the Anti Short Cycle time does not apply to recycle events such as loss of airflow or flame It applies only to loss of demand ZR Domestic Hot Water DHW Request The ZR terminal can be selected to service an indirect water heater heat request This parameter is set via the 3 digit display see Adjusting Settings section of this document A heat request via the ZR terminal will have priority over all other features such as the Anti Sh2. Voltage 120 Vac 60 Hz Power 7 VA maximum at 120 Vac plus external loads Thermostat current 100 mA nominal at 24 Vac Burner Relay 7 4 A at 120 Vac Full Load Amperage FLA 44 4 A inrush Locked Rotor Amperage LRA Less Ignition Load 360 VA Circulator Relay 7 4 A at 120 Vac FLA 44 4 A inrush LRA Zone Controller ZC 7 4 A at 120 Vac FLA 44 4 A LRA NOTE All loads combined cannot exceed 2000 VA Environmental Ratings Temperature 30 F to 150 F 34 C to 66 C Humidity 0 to 95 relative humidity noncondensing Approvals Underwriters Laboratories Inc Component Recognized Canadian Underwriters Laboratories Inc Component Recognized 2012 DOE Compliance and Operation Operation of this control may delay the burner operation while the residual heat is circulated out of the boiler NOTE This operation may be different than earlier electronic Aquastat revisions which did not implement thermal purge 68 0281 16 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS Accessories W8735Y1000 Wireless Outdoor Reset Kit W8735ER1000 Wireless Outdoor Reset Module C7089R1013 Wireless Outdoor Temperature Sensor requires W8735ER1000 W8735S1000 AquaReset Outdoor Reset Kit includes 50022037 002 Outdoor Reset Module and C7089U1006 Outdoor Temperature Sensor W8735S1008 AquaReset Domestic Hot Water Kit includes 50022037 005 Domestic Hot Water Mod
3. 6 MM QUICK CONNECT TERMINAL SOLDERLESS WIRE CONNECTION POWER SUPPLY PROVIDE DISCONNECT MEANS AND OVERLOAD A ENVIRACOM TERMINAL 3 IS ALSO THE FIRST THERMOSTAT TERMINAL PROTECTION AS REQUIRED OPTIONAL OUTDOOR RESET MODULE AND OUTDOOR SENSOR A OPTIONAL FEATURE ON SELECT MODELS W8735S1000 WIRED OUTDOOR RESET MODULE SHOWN JA REFERTO DEVICE LABEL FOR WIRE COLOR CODE A DUU MUST BE SET TO ON ON THE AQUASTAT M32025B A VALVE IS OPTIONAL ON SPECIFIED MODELS Fig 10 L7224A C single zone system with circulator and indirect water tank with EnviraCOM thermostat 12 68 0281 16 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS ELL OFF CM m CIRCULATOR uA HOT L2 R845A RELAY ZONE 2 ZONE 2 LOW VOLTAGE THERMOSTAT ENVIRACOM TERMINALS W8735Y1000 OR 873551000 LOW VOLTAGE THERMOSTAT L7248L 1 C7089U1006 SENSOR 1 OUTDOOR SENSOR W873581008 DOMESTIC HOT LINE WATER MODULE VOLTAGE CIRCULATOR LINE VOLTAGE 32003971 003 AR n TEMPERATURE SENSOR E A POWER SUPPLY PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED A CONTROL CASE MUST BE CONNECTED TO EARTH GROUND USE GROUNDING SCREW PROVIDED A OPTIONAL OUTDOOR RESET MODULE AND OUTDOOR SENSOR W8735S1000 WIRED OUTDOOR RESET MODULE SHOWN A ENVIRACOM TERMINALS A OPTIONAL DOMESTIC HO
4. Error condition 10 System continues to run with outdoor reset parameters enabled as programmed Error cleared automatically Error condition 11 System continues to run with boiler temp set to High Limit Error condition only available when the Outdo Table 7 L7224 L7248 Controller Operating Sequence with multiple zones connected through the ZR terminal or Reset Module is installed Action Zone Request ZR terminal is connected to L1 Zone calls for heat System Response Boiler temperature is checked Burner starts when water temperature is below High Limit setting or at or below the Thermal Purge Temperature Limit tPL for cold start boilers if the Thermal Purge Temperature Limit is enabled If tPL is enabled the burner may also start if the boiler temperature is cooling at 10 F or greater per minute or the Thermal Purge Time Delay tPt has expired Anti Short Cycle Time is applied see Table 6 Boiler temperature exceeds the High Limit Burner is turned off Burner restarts when the water temperature drops below the High Limit setting minus the Differential If Thermal Purge is enabled the burner is turned on when either the Thermal Purge Temperature Limit is reached the Thermal Purge Time Delay has expired or the boiler temperature cooling rate exceeds 10 F minute Zone Request input is de energized Zones are satisfied Burner turns off Boiler temperature drops below t
5. Guide System Diagnostic Condition Condition Check Action Boiler is hot Display is ON 120 Vac at C1 C2 120 Vac at C1 C2 check wiring to pump house is cold Wiring OK is pump running f not replace the pump If pump is running check for trapped air or closed zone valves Boiler below the Low Limit temperature wait for boiler to go above Low Limit temperature Boiler above LL If yes check for e If no 120 Vac replace control 120 Vac between ZC and L2 f yes check zone relays circulators and wiring ELL setting L7248L only Set ELL to Off for multizone system see Fig Set ELL to On for External Low Limit see Fig 13 Boiler above LL If yes check 120 If no 120 Vac check C1 C2 see above Vac at ZR L2 only L7248L with e If yes check the External Low Limit control ELL set On Boiler is hot Display is ON Boiler Demand signal from the 24 Vac on T T or 0 Vac on ZR L2 check no hot potable water heater either 120 Vac at wiring to water heater water ZR L2 or 0 Vac on T T depends e Wiring OK check the water heater on installation and duu setting duu setting Setduu to ON if 120 Vac water heater demand is connected to ZR Setduu to OFF if open closed w
6. control case 2 Position immersion well clamp snugly over the flange of the adapter and tighten the clamp screw 3 Insert the sensor into the well as shown in Fig 2 or 3 See Replacement Sensor Installation section for details THERMOSTAT TERMINALS DISPLAY FUSE 40 e WM E lo H e esia amp z s 8 s R ENVIRACOM SENSOR al TERMINALS CONNECTOR SENSOR HOLES M32186 Fig 3 Circuit board showing sensor connection and well holes for horizontal mount models 68 0281 16 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS SENSOR WIRES Pa BOILER IMMERSION WELL SENSOR HEAT CONDUCTIVE COMPOUND OPTIONAL M22026 Fig 4 Replacement sensor installation Replacement Sensor Installation Turn off all power and 1 Carefully disconnect sensor from circuit board by pulling gently on the connector 2 Gently pull sensor from thermo well and through cir cuit board by pulling on leadwires 3 Carefully align replacement sensor with hole in cir cuit board and guide through Aquastat case and into well See Fig 5 4 Make sure sensor is fully seated to bottom of well See Fig 4 Use a small pencil to meas
7. of the L7224A C L7248A C L or in Fig 8 13 Refer to Fig 6 for Connections for the optional Outdoor Reset Module and the Domestic Hot Water DHW module In subsequent wiring diagrams these modules will be displayed with a dotted line signifying that they are optional W8735Y1000 OR W873581000 OUTDOOR RESET MODULE W873581000 SHOWN 2 C7089U1006 OUTDOOR SENSOR W873581008 DOMESTIC HOT WATER MODULE 32003971 003 TEMPERATURE SENSOR M34961 Bie Fig 6 Wiring the Outdoor Reset Module and the Domestic Hot Water Module OPERATION General The L7224A C and L7248A C L Oil Electronic Aquastat Controllers are primary safety limit rated devices designed for use with oil fired boilers with line voltage burners and circulators Many boilers do not include wiring or control compartments as part of the design but are provided with an integral replaceable immersion well that is the mounting hardware for the Aquastat Controllers Wiring to the other controls is done through flexible metal conduit For boilers that do include a remotely flush mounted control the wiring may be completed with conduit or routed behind the boiler sheet metal L7224A C L7248A C L OIL AND ELECTRIC BOILER ELEC
8. Honeywell L7224A C L7248A C L Oil and Electric Boiler Electronic Aquastat Controllers APPLICATION The L7224A C and L7248A C L 2012 Compliant Electronic Aquastat Controllers provide electronic temperature sensing in a UL limit rated control with a single sensing probe The L7224A C and L7248A C L control the circulator oil or electric burner or contactor and boiler temperature The L7224 L7248 is Outdoor Temperature Reset ready which is enabled when connected to the W8735Y 1000 wireless or W8735S1000 wired Outdoor Reset Kit Outdoor Reset with the L7224 L7248 is intended for all applications except for tankless coil systems for domestic hot water Compliance to 2012 DOE regulation ensures efficiency is maximized without interfering with domestic hot water demand The L7224A C and L7248A C L replace the L8124A L8124C L7124A C L7148A and L8148A Controllers The L7224A C and L7248A C L series controls provide status and diagnostic information through an LED display combined with LED lights as well as EnviraCOM communications enabled thermostats and diagnostic tools to enhance the diagnostic process L7224 L7248 Aquastat Controllers are intended for use in residential type applications INSTALLATION INSTRUCTIONS IMPORTANT Use of Outdoor Temperature Reset on a tank less coil application requiring a Low Limit setting will result in reduced system effectiveness and efficiency SPECIFICATIONS Electrical Ratings
9. INALS MAY HAVE DIFFERENT LABEL CHECK PANEL MANUFACTURER SPECIFICATIONS FOR WIRING INSTRUCTIONS M32024A Fig 12 L7224 L7248 multizone system with Outdoor Reset and Domestic Hot Water Modules indirect tank applications 68 0281 16 14 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS ELL ON 12 L1 HOT L6006 LOW LIMIT CONTROLLER TN B LOW VOLTAGE THERMOSTAT L7248L SENSOR LINE VOLTAGE CIRCULATOR LINE VOLTAGE OIL BURNER RELAY E POWER SUPPLY PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED CONTROL CASE MUST BE CONNECTED TO EARTH GROUND USE GROUNDING SCREW PROVIDED M27113 Fig 13 L7248L External Low Limit connections 15 68 0281 16 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS Automation and Control Solutions Honeywell International Inc 1985 Douglas Drive North Golden Valley MN 55422 customer honeywell com U S Registered Trademark 2013 Honeywell International Inc 68 0281 16 M S Rev 09 13 Printed in United States Honeywell
10. OR EBL SENSOR E en LINE VOLTAGE L CIRCULATOR g T u LINE VOLTAGE oF OIL BURNER c RELAY OUTDOOR RESET MODULE IS OPTIONAL 1873551000 WIRED OUTDOOR RESET MODULE SHOWN A FOR BEST PERFORMANCE SET DUU 0N M32023A Fig 8 L7224A C L7248L single heat zone with indirect water tank and circulators Optional Outdoor Reset Module 68 0281 16 8 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS Table 6 L7224 L7248 Controller Operating Sequence Action Thermostat calls for heat System Response Circulator starts when water temperature is above Low Limit setting if applicable or above the Thermal Purge Temperature Limit tPL if Thermal Purge is enabled Boiler temperature is checked Burner starts when water temperature is below High Limit setting minus the differential or at or below the Thermal Purge Temperature Limit tPL for cold start boilers if the Thermal Purge Temperature Limit is enabled If tPL is enabled the burner may also start if the boiler temperature is cooling at 10 F or greater per minute or the Thermal Purge Time Delay tPt has expired If Anti Short Cycle Time is enabled the burner does not start until the set Anti Short Cycle Time between cycles expires after the previous call for heat was satisfied Boiler temperature exceeds the High Limit Burner is turned off Burner restarts when the water temperatu
11. T WATER MODULE AND TEMPERATURE SENSOR M29655A Fig 11 L7248L multizone system with circulator connections 13 68 0281 16 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS W8735Y1000 OR W8735S1000 W873581008 MULTI ZONE RELAY PANEL OUTDOOR SENSOR 32003971 003 TEMPERATURE SENSOR ENVIRACOM BURNER TERMINAL Es MOTOR IGNITER j 8 IGNITER VALVE CELL JUNCTION BOX LEGEND Q SCREW TERMINAL gt N 6 MM QUICK CONNECT TERMINAL SOLDERLESS WIRE CONNECTION VOLTAGE CIRCULATOR ro REMOTE ALARM I CIRCUIT POWER SUPPLY PROVIDE DISCONNECT MEANS AND OVERLOAD A OPTIONAL OUTDOOR RESET MODULE AND OUTDOOR SENSOR PROTECTION AS REQUIRED W873581000 WIRED OUTDOOR RESET MODULE SHOWN A OPTIONAL FEATURE ON SELECT MODELS A OPTIONAL DOMESTIC HOT WATER MODULE A REFER TO DEVICE LABEL FOR WIRE COLOR CODE WIRE ONLY THE ENVIRACOM TERMINALS 1 2 3 ON OIL PRIMARY IF CONNECTING TO REMOTE DIAGNOSTICS OTHERWISE CONNECT A VALVE IS OPTIONAL ON SPECIFIED MODELS A JUMPER BETWEEN THE TT TERMINALS A ENVIRACOM TERMINAL 3 IS ALSO THE FIRST THERMOSTAT TERMINAL A ZONE PANEL TERM
12. TRONIC AQUASTAT CONTROLLERS A separate electromechanical high limit is not required in a system that uses this control to meet Underwriters Laboratories Inc requirements for oil fired boiler assemblies UL 726 On the L7224 models the High Limit Low Limit Low Limit Differential and Anti Short Cycle time can be adjusted to the setting recommended by the boiler OEM On the L7248 models the High Limit and Anti Short Cycle time are also adjustable see Adjusting Settings The overall range of the High Limit is from 130 F to 240 F 54 C to 116 C Select devices may have different ranges Some models have limited ranges on the High Limit setpoint this limited range is listed on the device label Some models also have a Low Limit and Low Limit Differential adjustment The range of the Low Limit is from 110 F to 220 F 43 C to 104 C Select devices may have different ranges The Zr setting can be set to DHW Zoning or for tankless coil applications depending on the L7224 L7248 If an Outdoor Reset Module is installed the reset curve can be set by entering the minimum outdoor temperature minimum boiler temperature and maximum outdoor temperature on the 3 digit display The range of the minimum outdoor temperature is from 40 F to 40 F 40 C to 4 4 C and has a default setting of 0 F 18 C The range of the maximum outdoor temperature is from 30 F to 70 F 1 1 C to 21 1 C and has a d
13. ater heater demand is connected to T T Check DHW Module and DHW e DHW Module not properly connected and or Sensor DHW Sensor improperly positioned TO ADDITIONAL R845A ZONE2 CIRCULATOR RELAYS FOR OTHER ZONES Low VOLTAGE A 1 A THERMOSTAT L2 HOT L7224 R845A RELAY ZONE 2 HG rt T FG Ic HG SENSOR F ER 5 1 1 mo 2 LINE VOLTAGE E CIRCULATOR ZONE 2 LOW VOLTAGE THERMOSTAT ul e A POWER SUPPI LINE ep Q LY PROVIDE DISCONNECT MEANS AND OVERLOAD NNER Dle PROTECTION AS REQUIRED RELAY e cr Th CONTROL CASE MUST BE CONNECTED TO EARTH GROUND USE GROUNDING SCREW PROVIDED M27115 Fig 9 L7224A C multizone system with circulator connections 68 0281 16 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS LINE VOLTAGE hd W8735Y1000 OR INDIRECT TANK AQUASTAT W873581000 C7089U1006 OUTDOOR SENSOR INDIRECT TANK R7184 R7284 A B BURNER f ENVIRACOM TERMINAL MOTOR IGNITER IGNITER VALVE CIRCULATOR Iro TO REMOTE CAD ALARM ICIRCUIT GELL nmm uum ESI JUNCTION BOX LEGEND Z SCREWTERMINAL gt 14 IN
14. eature is automatically disabled whenever there is a call for domestic hot water either from the Zr terminal or from the DHW Module to insure hot water is available in a timely manner See ZR Domestic Hot Water DHW Request on page 7 Pump Cycling The Pump Cycling feature exercises the system pump for 15 seconds after a non adjustable five day period of no boiler activity The Pump Cycling feature default setting is enabled ON but can be disabled OFF using the 3 digit display See Adjusting Settings on page 5 CHECKOUT Put the system into operation and observe at least one complete cycle to make sure that the controller operates properly See TROUBLESHOOTING section to use LED to assist in determining system operation TROUBLESHOOTING When attempting to diagnose system performance reference to the LED display can help to identify specific areas not working properly The LED display will scroll Err followed by a digit 1 8 Refer to Table 10 and 11 for a description of each error and suggested actions 68 0281 16 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS LINE VOLTAGE INDIRECT TANK AQUASTAT Li W8735Y1000 OR HOT W8735S1000 INDIRECT L TANK 1 2 3OT OT IN Hor 12 _ CIRCULATOR 12 C7089U OUTDOOR T SENS
15. ed off Domestic Hot Water is satisfied Table 10 LED Error Codes Aquastat EnviraCOM Error Code Cause Action Alarm Err1 Aquastat sensor fault check water sensor 18 Err2 ECOM fault check EnviraCOM wiring 18 Err3 Excessive electrical noise or frequency out of range Hardware fault replace controller 18 58 Err4 B1 fault check B1 wiring voltage 64 Err5 Low Line check L1 L2 110 Vac 59 Err62 Warning Fuse check ECOM wires replace fuse 92 Err7 Warning EEPROM HL LL Hdf Ldf reset to default values N A Err 8 Repeated B1 fault voltage present at B1 when output is turned off check B1 wiring voltage 25 Err9a Warning Outdoor Reset System failure communication to Outdoor Reset Module lost 50 53 149 Outdoor Reset Module failure multiple outdoor temperature sensors detected on the bus or outdoor temperature sensor failure Check EnviraCOM wiring 1 2 3 check sensor wiring Err 108 Warning Boost Failure Boost Mode active at least once per cycle for the last 60 consecutive 150 cycles Check Outdoor Reset curve settings Err 118 DHW Module Sensor failure communication to DHW Module lost DHW Module failure or 146 147 temperature sensor failure Check EnviraCOM wiring 1 2 3 check sensor wiring 148 Warnings are generated to enunciate the system is not operating optimally but the Aquastat is still operating and maintaining boiler temperature In t
16. efault setting of 40 F The range of the minimum water or boiler temperature is from 80 F to 180 F 26 7 C to 82 2 C and has a default setting of 130 F See the Outdoor Reset Module Installation Instructions form number 69 2335 for more information on setting the boiler reset curve and all related parameters The L7224A C and L7248A C L are designed for use with 24 Vac electronic and electromechanical thermostats or EnviraCOM enabled thermostats and have screw type terminals for easy field connection Adjusting Settings To discourage unauthorized changing of Aquastat settings a procedure to enter the ADJUSTMENT mode is required To enter the ADJUSTMENT mode press the UP DOWN and I buttons Refer to Fig 5 simultaneously for three seconds Press the I button until the feature requiring adjustment is displayed Table 3 Adjustable Features Display Definition HL High Limit Hdf High Limit Differential LL Low Limit L7224A C Ldf Low Limit Differential L7224A C ELL External Low Limit L7248L only duu ZR input configured as external Domestic Hot Water DHW request ON OFF L7224A C L7248L ASC Anti Short Cycle Timeout seconds OFF is disabled otL Outdoor Temperature Low minimum parameter for the outdoor reset curve F or C otH Outdoor Temperature High maximum parameter for outdoor reset curve F or C btL Boiler Temperature Low
17. erature the burner is allowed to fire Thermal purge is only applied to cold start Aquastat models L7248 and will not interfere with domestic hot water call for heat or boilers equipped with Honeywell outdoor reset accessories For warm start models where a Low Limit must be set thermal purge is not applied In addition to the thermal purge temperature and thermal purge time delay parameters two other conditions release the Aquastat from thermal purge in order to maintain comfort in the space The boiler temperature has dropped 10 F from the beginning of the thermal purge Boiler temperature is cooling at a rate greater than 5 F minute while the circulator is running The thermal purge feature applies to single zone as well as multi zone applications Thermal Purge Settings Some thermal purge parameters are configurable using the 3 digit display See Adjusting Settings on page 5 Thermal purge may be disabled by setting the thermal purge temperature limit to OFF Table 5 Thermal Purge Settings Parameter name Minimum value Maximum Value Default Boiler temperature drop Not adjustable Not adjustable 10 F Thermal purge temperature limit 120 F or OFF 160 F 140 F L7248 Thermal purge temperature rate of drop Not adjustable Not adjustable 5 F minute Thermal purge time delay 1 minute 10 minutes 2 minutes Thermal Purge and Domestic Hot Water The thermal purge f
18. he Low Limit setting minus the differential if applicable Burner turns on and Zone Control is de energized Burner turns off and Zone Control is re energized when the water temperature exceeds the Low Limit setting 68 0281 16 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS Table 8 Controller Operating Sequence with External Low Limit device connected trough the ZR terminal Action System Response Zone Request ZR terminal is connected to Boiler temperature is checked Burner starts when water temperature L1 External Low Limit call for heat is below High Limit setting Circulator turns off Boiler temperature exceeds the High Limit Burner is turned off Burner restarts when the water temperature drops below the High Limit setting minus the Differential Zone Request input is de energized External Burner is turned off Low Limit is satisfied Table 9 L7224 Controller Operating Sequence with Domestic Hot Water connected trough the ZR terminal Action System Response Zone Request ZR terminal is connected to Boiler temperature is checked Burner starts when water temperature L1 Domestic Hot Water calls for heat is below High Limit setting Boiler temperature exceeds the High Limit Burner is turned off Burner restarts when the water temperature drops below the High Limit setting minus the Differential Zone Request input is de energized Burner is turn
19. he instance where an Outdoor Reset Module is used the warnings may indicate a reset curve setting error one or more features is not running optimally and the Aquastat is reverting to default settings or has stopped running the Outdoor Reset algorithms The warnings are cleared when the issue s is resolved To clear Err 8 condition depress and hold all three user keys simultaneously for 60 seconds Err 8 condition clears and display returns to normal Err 8 condition is designed to catch welded relays on the Aquastat and will normally only occur near end of life for the control If Err 8 condition has occurred early in the controls life be sure to check for voltage feedback to B1 when B1 should be off and check current draw on b terminal to be sure oil burner is not draw ing excessive current Err 8 condition will keep repeating if B1 fault is not cleared Table 11 Troubleshooting Guide System Diagnostic Condition Condition Check Action Boiler is cold Display is OFF 120 Vac System power Turn system power on house is cold Displayis ON 24 Vac T T No 24 V replace control 24 V present disconnect Boiler starts check wiring and thermostat thermostat short T T 120 Vac at B1 B2 f no replace control f yes check burner and wiring Refer to Err on display 68 0281 16 10 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS Table 11 Troubleshooting
20. iewable only if the outdoor reset module and out door temperature sensor are installed and functioning properly 3 Settings are viewable only if the domestic hot water module and sensor are installed and functioning properly Operation The L7224 and L7248 models can be in any of four operational states Normal High Limit Low Limit and Error The controller moves back and forth from High Limit to Normal to Low Limit state as part of normal operation Only devices having High Limit settings are restricted to the High Limit and Normal states However the controller will enter the Error state when there is an abnormal condition The operating states are 1 Normal Boiler temperature went below the High Limit setting minus the Differential and has not exceeded the High Limit setting or the boiler temperature went above the Low Limit setting and 68 0281 16 has not gone below the Low Limit setting minus the Differential or ZR input is not powered with 120 Vac only L7248L with ELL set On 2 High Limit Boiler temperature went above the High Limit setting and has not dropped below the High Limit setting minus the Differential 3 Low Limit Boiler temperature went below the Low Limit setting minus the Low Limit Differential and has not gone above the Low Limit setting or ZR input is powered with 120 Vac only L7248L with ELL set On 4 Error The controller has detected an error condition e g open sensor and has
21. ll power and drain the boiler if applicable 2 Ifnotapping is provided prepare properly sized and threaded tapping near the top of the boiler 3 Sparingly coat the well threads with pipe dope NOTE Do not attempt to tighten by using the case as a handle Install the well in the boiler tapping and tighten securely Refill boiler and check for water leakage Loosen but do not remove the well clamp screw Fit the case into the well so the clamp on the case slides over the flange on the well Securely tighten the clamp screw Insert the sensor element into the well until it bot toms See Replacement Sensor Installation section for details If necessary slightly bend the wire inside the case to hold the sensor against the bot tom of the well 10 Turn power ON 11 SetHigh Limit Low Limit and Low Limit Differential to the settings recommended by the boiler OEM See OPERATION section See INSTALLATION Steps 6 and 7 12 OnL7248L models adjust ELL option to match your configuration see OPERATION section and Fig 11 and 13 Noo IMPORTANT Best thermal response is obtained with a well that snugly fits the sensor Insert the sensor until it rests against the bottom of the well Use a well of correct length and bend the wiring if neces sary to hold the bulb against the bottom of the well If the well is not a snug fit on the sensor use the heat conductive compound furnished with TRADELINE mode
22. ls as follows Fold the plastic bag of compound lengthwise and twist it gently Then snip off end of bag and work the open end of the bag all the way into the well Slowly pull out the bag while squeezing it firmly to distribute compound evenly in the well Bend the wiring if necessary to hold the sensor against the bottom of the well and to hold outer end of the sensor in firm contact with the side of the well See Fig 2 Wipe excess compound from the outer end of the well SENSOR WIRES CONTROLLER CASE J BOILER HEAT CONDUCTIVE COMPOUND OPTIONAL IMMERSION WELL CLAMP IMMERSION WELL CLAMP SCREW M16120 Fig 2 Position of sensor in immersion well Flush Mounted Aquastat Replacement Turn off all power and remove the old control Refer to the cover insert of the old control to identify and tag each external lead as it is disconnected If the old well is unsuitable for the new installation remove it and replace it with a suitable new well If the old well is suitable use it Well Mounted Aquastat Replacement Turn off all power and remove the old control Refer to the cover insert of the old control to identify and tag each external lead as it is disconnected If the old well is unsuitable for the new installation remove it and proceed with instructions for new installation If the old well is suitable use it 1 Loosen but do not remove the well clamp screw on the side of the
23. minimum parameter for outdoor reset curve bP Boost Period minutes OFF is displayed if Boost is inactive bS Boost step F or C shown only if Boost is active DPZON UUS Warm Weather Shutdown Temperature F or C tPL Thermal Purging Limit Temperature F or C OFF if disabled tPt Termal Purging Time Delay minutes shown only if tPL is enabled PC Pump Cycling ON OFF F C Temperature units F or C Settings available for adjustment on the 3 digit display only if a W8735Y1000 or W8735S1000 Outdoor Reset Kit is installed Settings available for adjustment only when the W8735Y1000 or W873581000 Outdoor Reset Kit is NOT installed Then press the UP and or DOWN buttons to move the set point to the desired value to change between F and C or to enable On or disable Off the External Low Limit After 60 seconds without any button inputs the control will automatically return to the RUN mode Display In the RUN mode the Aquastat will flash bt boiler temp followed by the temperature i e 220 followed by F or C To read boiler settings press the I key to read the parameter of interest For example press I and High Limit HL is displayed followed by a three digit number i e 220 followed by F or C Pressing the I button again on L7224 models will display the Low Limit LL followed by a three digit number and the corre
24. mit and Low Limit Differential to the settings recommended by the boiler OEM 6 Record the maximum High Limit setting from the replaced controller in the text box provided on the cover insert label 7 Record the High Limit setting at time of installation in the text box provided on the cover insert label A WARNING Electrical Shock Hazard Can cause severe injury death or property damage Disconnect power supply before beginning installation to prevent electrical shock or equipment damage Mounting The L7224A C and L7248A C L models are available in a well mount horizontal position vertical position or flush mounted remote from the well versions Dimensions for the variety of mounting options are shown in Fig 1 Note that each identity will have only a single mounting option 1 1 8 29 lt lt 2 116 53 M22147B Fig 1 L7224A C L7248A C L mounting dimensions in inches mm IMPORTANT Immersion well must fit sensing element and sensor must rest against bottom of well 68 0281 16 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS New Installation Order well assemblies separately see Table 1 and form no 68 0040 Immersion Wells and Compression Fittings for Temperature Controllers Boilers usually have tappings that allow the well to be mounted horizontally so boiler water of average temperature can circulate freely over the well 1 Turn off a
25. ort Cycle feature or those enabled by the Outdoor Reset Module See form 469 2335 for more information Frost Protection The Frost Protection function protects the boiler and potentially the boiler plumbing from possible damage which may occur should the water in the system begin to freeze The Frost Protection feature is enabled only in the L7248 cold start models The feature default setting is enabled ON but can be disabled using the 3 digit display See Adjusting Settings on page 5 When the Boiler temperature drops to the Frost Protection Limit temperature fixed 40 F the burner is forced on The Circulator and ZC outputs remain in the same state as before the Frost Protection function was enabled They can be either ON or OFF during the Frost Protection cycle When the Boiler temperature reaches the Frost Protection Limit temperature plus a fixed 10 F differential the burner is turned off unless requested to stay on due to a different demand Thermal Purge Operation The intent of thermal purge is to insure usable residual heat in the boiler is circulated until it is sufficiently depleted from the system before the burner is allowed to fire To that end on a call for heat the burner is held off while the circulator runs until the boiler temperature drops to the thermal purge temperature or a time delay is exceeded Both of these parameters are adjustable When the boiler temperature reaches the thermal purge temp
26. re drops below the High Limit setting minus the Differential If Thermal Purge is enabled the burner is turned on when either the Thermal Purge Temperature Limit is reached the Thermal Purge Time Delay has expired or the boiler temperature cooling rate exceeds 10 F minute Thermostat is satisfied Circulator and burner turn off Boiler temperature drops below the Low Limit setting minus the differential if applicable Burner is turned on Circulator is turned off Burner stops when the water temperature exceeds the Low Limit setting Power to Zc is removed Error condition 1 5 If an error condition is detected all outputs except ZC are shut down Burner is off Control continues to function and restarts when error is corrected During the error check sequence the system checks for drift in the sensor and corrosion in the connections Error condition 6 EnviraCOM communication is not available Error condition 7 The control has reset the High Limit Low Limit and Differential setting to a default setting and will continue to run at those settings Performance of the system will be degraded Error condition 8 If the error condition is detected all outputs except ZC are shut down Burner is off Control continues to function and restarts when all three user keys have been pressed longer than 60 seconds Error condition 9 System continues to run with no outdoor reset functionality
27. shut down the burner output The ZC output is energized The controller continues to monitor the system and automatically restarts if the error condition clears Refer toTable 4 The operating sequence for the L7224 L7248 is shown in Table 6 9 High Limit Controller The High Limit opens and turns off the burner when the water temperature reaches the setpoint The High Limit automatically resets after the water temperature drops past the setpoint and through the Differential The L7248 models have High Limit Differential presets of 15 F 8 C The L7224 models have High Limit Differential presets of 10 F 6 C Low Limit and Circulator Controller On a temperature rise with the adjustable Differential at the default setting of 10 F 6 C the burner circuit breaks and the circulator circuit makes assuming no call for heat is present at the Low Limit setpoint On a temperature drop of 10 F 6 C below the Low Limit setpoint the burner circuit makes and the circulator circuit breaks See Fig 7 240 F 116 C L7224 10 F E DIFFERENCI L7248 DIFFERENCI 10 F 6 C DIFFERENCE 110 F 43 C SWITCH BREAKS ON TEMPERATURE RISE BURNER TURNS OFF HIGH LIMIT SETTING CIRCULATOR OPERATES ON A CALL FOR HEAT SWITCH MAKES ON TEMPERATURE FALL 4 BURNER OPERATES ON A CALL FOR HEAT LOW LIMIT SETTING 4 WITH NO HEATING DEMAND SWITCH BREAKS ON TEMPERATURE RISE A
28. sponding degree designator See Display Readout Table 4 After approximately 60 seconds without any key presses the display will enter a dim display mode To return to the bright display mode simply press any key 68 0281 16 L7224A C L7248A C L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT CONTROLLERS Table 4 Display readout definitions Text Description Display Err Error Code if one is present Err bT Boiler Temperature ht HL High Limit HL HdF High Limit Differential HdF LL Low Limit L7224 only LL Ldf Low Limit Differential L7224 only LdF it Local Thermostat Status Et HE EnviraCOM Thermostat Status EEE brn B1 Burner output ON or OFF brn Cir C1 Circulator output ON or OFF Lar 2 ZC Zone Control output ON or OFF eL Zr ZR Zone Request Call for HEAT ON or OFF Z ELL External Low Limit Enabled L7248L only ELL duu ZR Configured as Domestic Hot Water duu Request L7224 L7248L only ASC Anti Short Cycle Timeout ASE Boiler Set Point bSP dhe DHW Module Connected YES or NO dhc ot Outdoor Temperature 2 at otL Outdoor Temperature Low ntL otH Outdoor Temperature High btL Boiler Temperature Low 2 BEL bP Boost Period 2 bP bS Boost Step b5 UUS Warm Weather Shutdown Temperature 2 uus Display shows local setting not the setting as modified by an external enviracom control Settings are v
29. ule and 3200397 1 003 Sensor W8735S3000 EnviraCOM Alarm Module C7089U1006 Outdoor Temperature Sensor used with the 50022037 002 32003971 003 Temperature Sensor used with 50022037 005 Sensor See Table 2 120650 Heat Conductive Compound 121371AA Sensor Well Clamp Table 1 Wells for L7224A C L7248A C L Controllers Part Spud Size Insertion Insulation Number in mm in mm in mm 123869 1 2 12 7 3 76 2 1 1 2 38 1 123870A 3 4 19 05 NPT 3 76 2 1 1 2 38 1 Table 2 Sensors for L7224A C and L7248A C L Controllers Length in Part Number mm Application 50001464 001 12 304 8 Well mounted controls 50001464 003 24 609 6 Flush mounted controls 50001464 004 36 914 4 50001464 005 48 1219 2 34 ee 7 1 8 I 2 5 8 67 4 1 4 109 gt 4 1 16 2 3 13 32 86 2x 1 4 7 x 3 8 9 INSTALLATION When Installing this Product 1 Read these instructions carefully Failure to follow them could damage the product or cause a hazardous condition 2 Checkthe ratings given in the instructions and on the product to make sure the product is suitable for your application 3 Theinstaller must be a trained experienced service technician 4 After installation is complete check out product operation as provided in these instructions 5 SetHigh Limit Low Li
30. ure depth of sensor in well if necessary 5 Connect sensor to circuit board by pressing con nector on sensor unit into mating connector on cir cuit board See Fig 5 6 Forremote sensors flush mounted Aquastat Con trollers be sure to use 121571AA Clamp see Accessories to securely hold sensor in place ENVIRACOM TERMINALS THERMOSTAT TERMINALS gos DISPLAY SENSOR CONNECTOR RELAYS SENSOR HOLES FUSE M32187 Fig 5 Circuit board showing sensor connection and well holes for vertical mount models Fuse The 1 Amp fuse located near the transformer is intended to protect the EnviraCOM circuit from incorrect wiring The Aquastat will continue to function should the fuse blow or be removed though no EnviraCOM communication will be possible on the bus and Err 6 will be displayed See Table 10 68 0281 16 WIRING A WARNING Electrical Shock Hazard Can cause serious injury or death Disconnect power supply before making wiring connections to prevent electrical shock or equipment damage All wiring must comply with local electrical codes and ordinances Do not exceed the specifications in the Application section when wiring this control Use wire rated for 194 F 90 C or higher IMPORTANT The terminals on these Aquastat Controllers are approved for use with copper wire only Follow the appropriate wiring diagrams shown on the inside of the front cover
Download Pdf Manuals
Related Search