Home

Lennox International Inc. EL280UH Furnace User Manual

1. Flue Transition Collector Box Page 14 The EL280UH series units are classified as fan assisted Category furnaces when vertically vented according to the latest edition of National Fuel Gas Code NFPA 54 ANSI 2223 1 in the USA A fan assisted Category fur nace is an appliance equipped with an integral mechanical means to either draw or force combustion products through the combustion chamber and or heat exchanger The EL280UH is not approved for use with horizontal venting NOTE Use these instructions as a guide They do not su persede local codes This furnace must be vented accord ing to all local codes these installation instructions and the provided venting tables in these instructions The venting tables in this manual were extracted from the National Fuel Gas Code NFPA 54 ANSI 2223 1 and are provided as a guide for proper vent installation Proper ap plication termination construction and location of vents must conform to local codes having jurisdiction In the ab sence of local codes the NFGC serves as the defining doc ument Refer to the tables and the venting information contained in these instructions to properly size and install the venting system Use self drilling sheet metal screws or a mechanical fas tener to firmly secure the ven
2. External Air Volume Watts at Various Blower Speeds Static Medium Medium Pressure ind High Low addi in w g cfm Watts cfm Watts cfm Watts cfm Watts 0 10 2125 919 1820 747 1555 648 1300 540 0 20 2080 862 1790 705 1540 619 1335 516 0 30 2015 807 1745 652 1545 587 1335 498 0 40 1940 748 1695 629 1505 552 1320 470 0 50 1850 716 1635 581 1470 523 1295 449 0 60 1775 679 1575 560 1395 484 1235 417 0 70 1680 637 1470 508 1320 450 1170 387 0 80 1560 592 1350 469 1205 404 1050 345 NOTES air data is measured external to unit without filter not furnished field provided Page 37 BLOWER DATA EL280UH110P60C PERFORMANCE Less Filter Air Volume Watts at Different Blower Speeds External Bottom Return Air Side Return Air with Optional Return Single Side Return Air Air volumes in bold require field Static Air Base Return Air from Both Sides or Return Air from fabricated transition to accommodate 20 x 25 x 1 in air filter Pressure Bottom and One Side in order to maintain proper air velocity in w g High Medium High Medium Low Low High Medium High Medium Low Low cfm Watts cfm Watts cfm Watts cfm Watts cfm cfm Watts cfm Watts cfm Watts 0 10 2520 1359 2250 1034 1860 841 1455 654 2605 1454 2160 1060 1740 848 1430 65
3. 603 25 635 TOP VIEW 27 3 4 Front Panel 3 76 Right 7 178 Left 9 16 14 705 3 1 4 83 19 7 16 494 9 1 8 232 Right 3 OPTIONAL 8 5 8 219 Left EXTERNAL SIDE RETURN 2 FLUE OUTLET Either Side amp GAS PIPING INLET Either Side AIR FILTER KIT Either Side 5 3 8 137 Right 2 3 4 70 Left 33 838 a m a m m ae ee t al AIR FLOW C ef Js ELECTRICAL INLET ee _ Either Side 23 584 Side Return Air Opening Either Side 856 Y 1 15 16 49 23 1 2 Bottom Return Air Opening FRONT VIEW EL280UH Model No 070P24A 070 X P36A 090P36B 090 X P48B 110P48C 410 X P60C 135P60D 24 1 2 446 16 3 8 416 19 7 8 504 23 3 8 533 622 546 597 Bottom Return Air Opening SIDE VIEW Parts Arrangement Make Up Box Heat Exchanger Combustion Air Inducer Combustion Air Pressure Switch Gas Valve and Manifold Assembly Indoor Blower and Motor Assembly installed in cabinet Limit Switch under collector box Door Interlock Switch Indo
4. Once the venting system is installed attach the Dis connected Vent warning sticker to a visible area of the plenum near the vent pipe See figure 23 The warning sticker is provided in the bag assembly Or der kit 66W04 for additional stickers AWARNING Asphyxiation hazard The exhaust vent for this fur nace must be securely connected to the furnace flue transition at all times VENT CONNECTION UPFLOW AND HORIZONTAL POSITION DISCONNECTED VENT WARNING STICKER OPTIONAL SIDE VENTING VENT PIPE length min 6 length FLUE TRANSITION COLLAR DISCONNECTED VENT WARNING FLUE TRANSITION COLLAR VENT PIPE min 6 length FIGURE 23 Page 15 Common Venting Using Metal Lined Masonry Chimney i SEALED MAX LENGTH SEE NOTE 1 22 BELOW 1 5 m MIN LENGTH AS EXTERIOR CHIMNEY WITH METAL LINER imum SHORT AS PRACTICAL AA VENT CONNECTOR Y 4 in 102 mm minimum FURNACE PERMANENTLY SEALED FIREPLACE OPENING NOTE 1 Refer to the provided venting tables for installations Refer to the capacity requirements shown in the provided venting tables FIGURE 24 DO NOT insulate the space between the liner and the chimney wall with puffed mica or any other loose gran ular insulating material AIMPORTANT SINGLE appliance venting of a fan assisted furnace into a tile lined masonry chimney in
5. These instructions are intended as a general guide and do not supersede local codes in any way Consult authorities having jurisdiction before installation In addition to the requirements outlined previously the fol lowing general recommendations must be considered when installing a EL280UH furnace e Place the furnace as close to the center of the air dis tribution system as possible The furnace should also be located close to the chimney or vent termination point Page 5 e Do not install the furnace where drafts might blow direct ly into it This could cause improper combustion and un safe operation e Do not block the furnace combustion air openings with clothing boxes doors etc Air is needed for proper combustion and safe unit operation e When the furnace is installed in an attic or other insu lated space keep insulation away from the furnace NOTE The Commonwealth of Massachusetts stipu lates these additional requirements e Gas furnaces shall be installed by a licensed plumb er or fitter only e The gas cock must be T handle type e When a furnace is installed in an attic the passage way to and service area surrounding the equipment shall be floored AWARNING Product contains fiberglass wool Disturbing the insulation in this product during installation maintenance or repair will expose you to fiberglass wool Breathing this may cause lung cancer Fiberglass wool is known to the State of Cal if
6. 10 Remove heat exchanger It may be necessary to spread cabinet side to allow more room If so remove five screws from the left side or right side of cabinet See figure 38 11 Backwash using steam Begin from the burner opening on each clam Steam must not exceed 275 F 12 To clean burners run a vacuum cleaner with a soft brush attachment over the face of burners Visually inspect in side the burners and crossovers for any blockage caused by foreign matter Remove any blockage Figure 36 shows burner detail 13 To clean the combustion air inducer visually inspect and using a wire brush clean where necessary Use com pressed air to clean off debris and any rust 14 Reinstall heat exchanger in vestibule Replace the five screws in the cabinet from step 10 if removed 15 NOx units only Replace NOx inserts 16 Reinstall collector box and combustion air assembly Reinstall all screws to the collector box and combustion air inducer Failure to replace all screws may cause leaks Inspect gaskets for any damage and replace if necessary 17 Reinstall burner box manifold assembly and burner box cover EL280UH NOx INSERTS NOx Insert FIGURE 37 Remove 5 screws if necessary either side of cabinet FIGURE 38 18 Reconnect all wires 19 Reconnect top cap and vent pipe to combustion air in ducer outlet 20 Reconnect gas supply piping 21 Turn on power and gas supply to unit 22 Set thermostat an
7. ERROR CODE RECALL H 24V HUMIDIFIER OUTPUT L LENNOX SYSTEM OPERATION MONITOR 0 THERMOSTAT SIGNAL TO HEAT PUMP REVERSING VALVE pm _ DIP SWITCHES DIP SWITCH FUNCTIONS DIP SWITCH ES FUNCTION 1 2 Stage T stat Selects t stat type single or two stage 2 2nd Stage Dela Second stage ON delay single stage t stat 3 amp 4 Heat Off Dela Heating fan OFF dela 5 Cool Off Dela Cooling fan OFF dela FIGURE 33 Page 30 Integrated Control EL280UH units are equipped with a two stage integrated control This control manages ignition timing and fan off delays based on selections made using the control DIP switches The control includes an internal watchguard fea ture which automatically resets the integrated control when it has been locked out After one hour of continuous ther mostat demand for heat the watchguard will break and re make thermostat demand to the furnace and automatically reset the control to relight the furnace DIP Switch Settings Switch 1 Thermostat Selection This unit may be used with either a single stage or two stage thermostat The thermostat selection is made using a DIP switch which must be properly positioned for the particular application The DIP switch is factory positioned for use with a two stage thermostat If a single stage thermostat is to be used the DIP switch must be repositioned a Select OFF for two stage heating operation con trolled by a two stage heating thermostat
8. The bolt and washer must be removed before the furnace is placed into opera tion After the bolt and washer have been removed the rig id leg will not touch the blower housing EL280UHO90P48B and EL280UH110P48C with 1 2 HP BLOWER MOTOR A RIGID LEG remove shipping bolt and washer FIGURE 7 Upflow Applications Allow for clearances to combustible materials as indicated on the unit nameplate Minimum clearances for closet or al cove installations are shown in figure 8 Upflow Application Installation Clearances Left Side Right Side Bottom Type of Vent _ ee ae ee Front 2 1 4 in 57 mm 2 1 4 57 mm Front clearance in alcove installation must be 24 in 610 mm Maintain a minimum of 24 in 610 mm for front service access 4 1 2 in if single wall vent pipe is used For installation on a combustible floor do not install the furnace directly on carpeting tile or other combustible materials other than wood flooring tLeft side requires 3 inches if a single wall vent is used on 14 1 2 in cabinets or 2inches if a single wall vent pipe is used on 17 1 2 in cabinets FIGURE 8 Page 9 Return Air Upflow Applications Single Side Return Air Return air can be brought in through the bottom or either with transition and filter side of the furnace installed in an upflow application If the furnace is installed on a platform with bottom return make an airtight seal between the bot
9. 28 EL280UH SCHEMATIC WIRING DIAGRAM BLOWER SPEED CHART FACTORY CONNECTED SPEED TAPS MOTOR SECONDARY S10 UNIT HI 10 SPEEDS LIMITS PRIMARY COMBUSTION AIR Lom O CooL vicar PARK ava e A on INDUCER MOTOR Tell LIMIT VALVE 070P36A BLACKYELLOWV RED _ BROWM 4 2 5102 HIGH HEAT PRESSU BROWN YELLOW RED BLAC BLAC s128 LU7OXPSSABLACK YELLOW RED BROW EA LON HEAT RED BROW ROLLOUT PRESSI SWITCH BLOWER SPEED SELECTION Lo SPEED Taps BLACK BROWN YELLOW RED LAC 4 Ea E 4 JACKPLUGCHART JACKIPLUG COMB AIR INDUCER S21 92 SECONDARY THERMOSTAT HEAT ANTICIPATION SETTING CONTROL SUAMP 13 AMP WHITE RODGERS VALV EAE JUMPER W915 FROM Y1 TO Y2 LABELED 2 STAGE COMPR IS FACTORY INSTALLED AT A92 CONTROL BOARD LEAVE IN FOR ONE STAGE COOL THERMOSTAT CUT JUMPER FOR TWO STAGE COOL THERMOSTAT GAPAGITOR FACTORY DEFAULT IS FOR A 2 STAGE THERMOSTAT CUT W951 JUMPER FROM O TO R LABELED HEAT PUMP AT A92 CONTROL BOARD WHEN USED FOR DUAL FUEL APPLICATIONS FOR CORRECT NUMBER OF SECONDARY S1 ROOM THERMOSTAT T STAT HEAT STG m 2ND STG DELAY J HEAT OFF DELAY COOL OFF DELAY INTERLOCK J PRET REET LIMITS USED SEE SECONDARY LIMIT INDOOR SECTION OF BLOWER SPEED CHART BLOWER IMPORTANT MOTOR TO PREVENT MOTOR BURNOUT NEVER CONNECT M
10. 5 4 9 1 5 4 9 1 This is the only permissible derate for these units 2 Natural gas high altitude orifice kit required 3 A natural to L P propane gas changeover kit is necessary to convert this unit Refer to the changeover kit installation instruction for the conversion procedure NOTE Units may be installed at altitudes up to 4500 ft above sea level without modifications TABLE 15 Pressure Switch and Gas Conversion Kits at all Altitudes 5 High Altitude LP Propane to E High Altitude Pressure Switch Kit Natural Gas Kit LP Propane Gas Kit Natural Kit 0 4500 ft 4501 7500 ft 7501 10 000 ft 7501 10 000 ft 0 7500 ft 7501 10 000 ft 0 7500 ft Min 91W53 73W35 91W53 73W35 No Change 73W37 77W07 77W11 77W09 110 91W53 73W35 135 73W33 73W34 NOTE A natural to L P propane gas changeover kit is necessary to convert this unit Refer to the changeover kit installation instruction for the conversion procedure Page 34 Other Unit Adjustments Primary and Secondary Limits The primary limit is located on the heating compartment vestibule panel The secondary limits if equipped are lo cated in the blower compartment attached to the back side of the blower These auto reset limits are factory set and re quire no adjustment Flame Rollout Switches This manually reset switches are located on the baffle plate in the burner assembly Pressure Switch The pressure switch is located in the heating compa
11. 58 SIDE RETURN AIR BASE 7 1 4 AIR OPENINGS 143 OPENINGS _ 043 Either Side 23 4 1 2 368 A Width eu OPTIONAL 584 17 1 2 446 B Width 50w98 RETURN AIR BASE 26 7 8 21 533 C Width 50W99 683 24 1 2 622 D Width 51W00 SIDE VIEW NOTE Optional Side Return Air Filter Kits are not for use with Optional Return Air Base 1 Both the unit return air opening and the base return air opening must be covered by a single plenum or IAQ cabinet Minimum unit side return air opening dimensions for units requiring 1800 cfm or more of air W x H 23 x 11 in 584 x 279 mm The opening can be cut as needed to accommodate plenum or IAQ cabinet while maintaining dimensions shown Side return air openings must be cut in the field There are cutting guides stenciled on the cabinet for the side return air opening The size of the opening must not extend beyond the markings on the furnace cabinet 2 To minimize pressure drop the largest opening height possible up to 14 inches is preferred FIGURE 10 Page 10 Removing the Bottom Panel Remove the two screws that secure the bottom cap to the furnace Pivot the bottom cap down to release the bottom panel Once the bottom panel has been removed reinstall the bottom cap See figure 11 Removing the Bottom Panel Bottom Cap Horizontal Application Installation Clearan
12. If an adjustment is made on high fire re check man ifold pressure on low fire Do not adjust low fire man ifold pressure f low fire manifold pressure is more than 1 2 above or below value specified in table 14 replace valve NOTE Shut unit off and remove manometer as soon as an accurate reading has been obtained Turn the supply and manifold 3 32 hex screw one revolution back into the gas valve Proper Combustion Furnace should operate minimum 15 minutes with correct manifold pressure and gas flow rate before checking com bustion Table 13 shows acceptable combustion for ALL EL280UH models The maximum carbon monoxide reading should not exceed 50 ppm TABLE 13 High Fire 6 8 7 4 7 5 9 0 High Altitude The manifold pressure may require adjustment and com bustion air pressure switch may need replacing to ensure proper combustion at higher altitudes Refer to table 14 for manifold pressure and table 15 for pressure switch change and gas conversion kits Page 33 TABLE 14 Manifold Pressure Settings at all Altitudes Manifold Manifold Manifold Supply Line Pressure in wg Pressure in wg Pressure in wg Pressure 0 4500 ft 4501 7500 ft 7501 10 000 ft 2 in w g LowFre Woh Fre Win vax Lor 3s s pus m ws pus 38 7 3s 32 xr 3s s 6 4s s s o 3s 2 wr 3s 4s m o 1 6 4 9 1 5 4 9 1
13. PIPE Secure to Unit Elbows Secured to Pipe Roof Flashing water tight Vent Pipe Supported Line Voltage AIR gt upflow furnace shown Filter x RETURN AIR A Page 50 Ll LJ LJ LJ LJ L DUCT SYSTEM SUPPLY AIR DUCT Sealed Insulated if necessary Registers Open and Unobstructed RETURN DUCT Sealed Filter Installed and Clean Grilles Unobstructed INTEGRATED CONTROL DIP Switches Set if applicable Appropriate Links in Place if applicable VOLTAGE CHECK Supply Voltage Electrical Connections Tight Combustion Gas Manifold Pressure Q hermostat UNIT OPERATION typical R SUPPLY AIR Temperatures Filter RETURN AIR HEATING MODE COOLING MODE GAS MANIFOLD PRESSURE W C 5 INDOOR BLOWER AMPS 2 COMBUSTION SAMPLE CO PPM 5 INDOOR BLOWER AMPS TEMPERATURE RISE Supply Duct Temperature Return Duct Temperature Temperature Rise TOTAL EXTERNAL STATIC dry coil Supply External Static Return External Static Total External Static Contractor s Name Job Address G TEMPERATURE DROP Return Duct Temperature Supply Duct Temperature Temperature Drop TOTAL EXTERNAL STATIC dry coi
14. Secondary limit Page 42 Integrated Control Diagnostic Codes ae i as STATUS ERROR DESCRIPTION FLASH CODE DESCRIPTIONS Pus A 1 4 second flash followed by four seconds of off time Heartbeat Constant 1 2 second bright and 1 2 second dim cycles x y LED flashes X times at 2Hz remains off for two seconds flashes Y times at 2Hz remains off for four seconds then repeats Power on Standby Normal operation signaled when heating demand initiated at thermostat FLAME CODES Low flame current run mode Heartbeat 1 2 1 3 Flame sensed out of sequence flame still present PRESSURE SWITCH CODES Low pressure switch failed open Low pressure switch failed closed 2 3 2 4 2 5 2 6 2 7 High pressure switch failed open High pressure switch failed closed Low pressure switch opened during ignition trial or heating demand LIMIT CODE Co Limit switch open WATCHGUARD CODES Watchguard Exceeded maximum number of retries Watchguard Exceeded maximum number of retries or last retry was due to pressure switch opening Watchguard Exceeded maximum number of retries or last retry was due to flame failure Watchguard Limit remained open longer than three minutes Watchguard Flame sensed out of sequence flame signal gone Ignitor circuit fault Failed ignitor or triggering circuitry Low line voltage HARD LOCKOUT CODES Hard lockout Rollout circuit open or previously opened Co
15. cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts 0 10 2750 1441 2220 1056 1725 825 1395 625 2725 1463 2180 1075 1715 827 1320 624 0 20 2720 1392 2235 1029 1785 810 1445 618 2640 1400 2180 1051 1720 819 1380 626 0 30 2605 1362 2220 1002 1820 800 1460 623 2575 1374 2165 1005 1790 803 1420 622 0 40 2495 1312 2185 968 1845 779 1485 616 2495 1343 2145 988 1775 791 1450 617 0 50 2420 1275 2135 939 1825 767 1505 605 2405 1292 2105 948 1780 777 1470 610 0 60 2335 1234 2080 909 1825 753 1495 593 2305 1257 2045 914 1775 753 1480 593 0 70 2220 1190 1995 864 1760 716 1475 576 2215 1214 1970 884 1740 727 1455 583 0 80 2120 1157 1890 835 1680 686 1435 558 2110 1170 1890 851 1675 699 1430 565 NOTES All air data is measured external to unit without filter not furnished field provided Page 38 Service AWARNING ELECTRICAL SHOCK FIRE OR EXPLOSION HAZARD Failure to follow safety warnings exactly could result in dangerous operation serious injury death or property damage Improper servicing could result in dangerous opera tion serious injury death or property damage Before servicing disconnect all electrical power to
16. factory set ting b Select ON for two stage heating operation con trolled by a single stage heating thermostat This set ting provides a timed delay before second stage heat is initiated Switch 2 Second Stage Delay Used with Single Stage Thermostat Only This switch is used to deter mine the second stage on delay when a single stage ther mostat is being used The switch is factory set in the OFF position which provides a 10 minute delay before second stage heat is initiated If the switch is toggled to the ON position it will provide a 15 minute delay before second stage heat is initiated This switch is only activated when the thermostat selector jumper is positioned for SINGLE stage thermostat use Switches 3 and 4 Heating Blower Off Delay The heating blower on delay of 30 seconds is not adjustable The heating blower off delay time that the blower operates after the heating demand has been satisfied can be ad justed by moving switches 3 and 4 on the integrated con trol The unit is shipped from the factory with a heating blower off delay of 90 seconds The heating blower off delay affects comfort and is adjustable to satisfy individual applications Adjust the blower off delay to achieve a sup ply air temperature between 90 and 110 F at the exact moment that the blower is de energized Longer off delay settings provide lower supply air temperatures shorter set tings provide higher supply air temperatu
17. gauge connection See figure 34 6 In some localities codes may require the installation of a manual main shut off valve and union furnished by the installer external to the unit The union must be of the ground joint type AIMPORTANT Compounds used on threaded joints of gas piping must be resistant to the actions of liquified petro leum gases NOTE If emergency shutoff is necessary shut off the main manual gas valve and disconnect main power to the fur nace The installer should properly label these devices TABLE 9 Gas Pipe Capacity ft3 hr m3 hr Nominal Iron Pipe Internal Length of Pipe feet m inches inches 10 20 30 40 50 60 70 80 90 100 mm mm 3 048 6 096 9 144 12 192 15 240 18 288 21 336 24 384 27 432 30 480 1 2 622 172 118 95 81 72 65 60 56 52 50 E arti 48 d em aby eie ce no ein oa 3 4 824 360 247 199 170 151 137 126 117 110 104 19 05 20 930 10 19 7 00 5 63 A 81 A 28 3 87 3 56 3 31 3 11 2 94 1 1 049 678 466 374 320 284 257 237 220 207 195 254 26 645 19 19 13 19 10 59 9 06 8 04 7 27 6 71 6 23 5 86 5 52 1 1 4 1 380 1350 957 768 657 583 528 486 452 424 400 31 75 85 052 38 22 27 09 22 25 18 60 16 50 14 95 13 76 12 79 12 00 11 33 95 13 12 1 1 2 1 610 2090 1430 1150 985 873 791 728 677 635 38 1 40 894 59 18 4
18. heating mode when the combustion air inducer is operat ing Any humidifier rated up to one amp can be connected to this terminal with the neutral leg of the circuit being con nected to one of the provided neutral terminals If a humidi fier rated at greater than one amp is connected to this termi nal it is necessary to use an external relay relay Generator Use Voltage Requirements The following requirements must be kept in mind when specifying a generator for use with this equipment The furnace requires 120 volts 10 Range 108 volts to 132 volts e The furnace operates at 60 Hz 5 Range 57 Hz to 63 Hz e furnace integrated control requires both polarity and proper ground Both polarity and proper grounding should be checked before attempting to operate the furnace on either permanent or temporary power e Generator should have wave form distortion of less than 5 total harmonic distortion THD Thermostat Install the room thermostat according to the instructions provided with the thermostat See table 10 for thermostat designations If the furnace is being matched with a heat pump refer to the FM21 installation instruction or appropri ate dual fuel thermostat instructions Indoor Blower Speeds 1 When the thermostat is set to FAN ON the indoor blower will run continuously on the low speed when there is no cooling or heating demand 2 When the EL280UH is operating in the high fire or low
19. high fire After 10 to 20 seconds of high fire operation the unit will switch to low fire NOTE If the furnace is operating on continuous fan mode terminal R and G are energized the combustion air in ducer will energize on high speed the gas valve will ener gize on second stage heat and the furnace will operate on high fire Furnace will stay on high fire for 60 seconds then switch to low fire 2 SureLight control begins 20 second ignitor warm up period 3 Gas valve opens on first stage for a 4 second trial for ignition Ignitor stays energized during the trial or until flame sensed 4 Flame is sensed gas valve remains on first stage heat ignitor de energizes 5 After 30 second delay indoor blower B3 is energized on low heat speed The furnace will stay in this mode until first stage de mand is satisfied OR a second stage heat demand is initiated 6 Second stage heat demand initiated A 30 second sec ond stage recognition period begins 7 The combustion air inducer ramps up to high heat speed 8 102 high heat prove switch closes and the gas valve energizes second stage heat 9 indoor blower switches to high heat speed Single Stage Thermostat Two Stage Heat Dip Switch set at SINGLE 1 SureLight control energizes combustion air inducer B6 on low heat speed Combustion air inducer runs until 128 low heat prove switch contacts close switch must close within 2 1 2 minutes or control goes into
20. make sure the wires will be long enough for servicing at a later date Make sure that thermostat wire is long enough to facilitate future removal of blower for service Complete the wiring connections to the equipment Use the provided unit wiring diagram and the field wiring diagram shown in figure 32 Use 18 gauge wire or larger that is suit able for Class rating for thermostat connections Electrically ground the unit according to local codes or in the absence of local codes according to the current Na tional Electric Code ANSI NFPA No 70 A green ground wire is provided in the field make up box NOTE The EL280UH furnace contains electronic compo nents that are polarity sensitive Make sure that the furnace is wired correctly and is properly grounded Accessory Terminals One line voltage EAC 1 4 spade terminal is provided on the furnace integrated control See figure 33 for integrated control configuration This terminal is energized when the indoor blower is operating Any accessory rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to one of the provided neutral terminals If an accessory rated at greater than one amp is connected to this terminal it is necessary to use an exter nal relay One line voltage HUM 1 4 spade terminal is provided on the furnace integrated control See figure 33 for integrated control configuration This terminal is energized in the
21. pressure that exceeds 0 5 inches w c Higher external static pressures may cause erratic lim it operation Supply Air Plenum If the furnace is installed without a cooling coil a removable access panel must be installed in the supply air duct The access panel should be large enough to permit inspection either by smoke or reflected light of the heat exchanger for leaks after the furnace is installed The furnace access panel must always be in place when the furnace is operat ing and it must not allow leaks into the supply air duct sys tem Return Air Plenum NOTE Return air must not be drawn from a room where this furnace or any other gas fueled appliance i e water heater or carbon monoxide producing de vice i e wood fireplace is installed When return air is drawn from a room a negative pres sure is created in the room If a gas appliance is operating in a room with negative pressure the flue products can be pulled back down the vent pipe and into the room This reverse flow of the flue gas may result in incomplete com bustion and the formation of carbon monoxide gas This toxic gas might then be distributed throughout the house by the furnace duct system In upflow applications the return air can be brought in through the bottom or either side of the furnace If a fur nace with bottom return air is installed on a platform make an airtight seal between the bottom of the furnace and the platform to ensure that
22. 0 49 32 56 27 89 24 72 22 39 20 61 19 17 17 98 38 1 4049 32 56 27 89 24 72 2 2 067 4020 2760 2220 1900 1680 1520 1400 1300 1220 1160 eis es crass 600 17 00 34 2 1 2 2 469 6400 4400 3530 3020 2680 2480 2230 2080 1950 1840 63 5 67 713 181 22 124 59 99 95 85 51 75 88 70 22 63 14 58 89 55 22 52 10 3 3 068 11300 7780 6250 5350 4740 4290 3950 3670 3450 3260 76 2 77 927 319 98 220 30 176 98 151 49 134 22 121 47 111 85 103 92 97 69 92 31 NOTE Capacity given in cubic feet m of gas per hour and based on 0 60 specific gravity gas Page 23 Left Side Piping Standard MANUAL MAIN SHUT OFF VALVE With 1 8 Plugged Tap Shown GROUND DRIP LEG MANUAL MAIN SHUT OFF GROUND JOINT UNION DRIP LEG gt Horizontal Application Right Side Air Discharge AUTOMATIC GAS VALVE FIELD PROVIDED AND INSTALLED NOTE BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET FIGURE 26 Horizontal Applications Possible Gas Piping Configurations MANUAL AUTOMATIC GAS VALVE MAIN SHUT OFF VALVE GROUN JOINT D UNION DRIP LEG FIELD PROVIDED AND INSTALLED NOTE BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF FIGURE 27 Page 24 CABINET MANUAL IAIN SHUT OFF VALVE With 1 8 in
23. 1 0 20 2465 1329 2230 1018 1870 823 1480 647 2505 1401 2150 1018 1785 838 1450 649 0 30 2385 1307 2180 981 1885 809 1540 646 2435 1349 2115 991 1795 818 1485 638 0 40 2295 1256 2105 942 1865 778 1570 638 2350 1308 2070 965 1805 801 1480 631 0 50 2200 1214 2055 909 1845 762 1570 619 2260 1274 2010 929 1785 775 1480 621 0 60 2130 1186 1985 882 1795 741 1550 604 2175 1228 1955 901 1755 752 1490 611 0 70 2015 1150 1890 848 1720 711 1505 580 2085 1186 1850 853 1710 722 1460 594 0 80 1905 1105 1810 815 1675 687 1470 565 1965 1147 1785 818 1640 689 1425 567 NOTES All air data is measured external to unit without filter not furnished field provided EL280UH135P60D PERFORMANCE Less Filter Air Volume Watts at Different Blower Speeds External Bottom Return Air Side Return Air with Optional Return Single Side Return Air Air volumes in bold require field Static Air Base Return Air from Both Sides or Return Air from fabricated transition to accommodate 20 x 25 x 1 in air filter Pressure Bottom and One Side in order to maintain proper air velocity in w g High Medium High Medium Low Low High Medium High Medium Low Low cfm Watts cfm Watts cfm Watts
24. 43 47 50 50 53 55 54 57 62 64 TABLE 6 Common Vent Capacity Type B Double Wall Vents with Type B Double Wall Connectors Serving Two or More Category 1 Appliances Common Vent Diameter D inches amn J Sm omn J 7mh Appliance Input Rating in Thousands of Btu Per Hour FAN FAN FAN NAT FAN FAN FAN NAT FAN FAN FAN NAT FAN FAN FAN NAT 24 t 39 x s j m s wow r j s z __ x 99 s m m 2 m 3 2 r r m z z s _ m 39 29 2 3 3 1 s 2 L z 1 s L z L sz L J Page 20 TABLE 7 Vent Connector Capacity Type B Double Wall Vents with Single Wall Metal Connectors Serving Two or More Category 1 Appliances Vent and Connector Diameter D inches Lateral Lax shi amen a ipeo 7 Appliance Input Rating in Thousands of Btu Per Hour MAX MAX wa 1 19 25 ws es r Oor a _ 9 230 23 umo alc qoem n ws m5 82 252 t 29 L9 2 s s rs t 3 NOTE Single appliance venting configurations with zero lateral lengths are assumed to have no elbows in the vent system For all other vent configurations the vent system is assumed to have two 90 elbows For each additional 90 elbow or equivalent for example two 45 elbows equal one 90
25. 50 cu bic feet 1 42 m3 per 1 000 Btu 29 kW per hour of the combined input rating of all appliances installed in that space This definition includes furnace closets or small equipment rooms When the furnace is installed so that supply ducts carry air circulated by the furnace to areas outside the space contain ing the furnace the return air must be handled by ducts which are sealed to the furnace casing and which terminate outside the space containing the furnace This is especially important when the furnace is mounted on a platform in a confined space such as a closet or small equipment room Even a small leak around the base of the unit at the platform or at the return air duct connection can cause a potentially dangerous negative pressure condition Air for combustion and ventilation can be brought into the confined space either from inside the building or from outside EQUIPMENT IN CONFINED SPACE ALL AIR FROM INSIDE CHIMNEY OR GAS VENT FURNACE OPENINGS To Adjacent Room NOTE Each opening shall have a free area of at least one square inch 645 mm per 1 000 Btu 29 kW per hour of the total input rat ing of all equipment in the enclosure but not less than 100 square inches 64516 mm FIGURE 3 Air from Inside If the confined space that houses the furnace adjoins a space categorized as unconfined air can be brought in by providing two permanent openings between the two spaces Each opening must have a
26. ATION THERMOSTAT CALLS FOR HEAT STATUS LED HEARTBEAT SEE BOX A CONTINUED FLAME SIGNAL ABOVE gt 1 40 microamps LOW FLAME SIGNAL Does not affect control operation STATUS ERROR CODE 1 2 SINGLE STAGE THERMOSTAT MODE L DIP SWITCH SET AT SINGLE START SECOND STAGE RECOGNITION 45 SECOND INDOOR BLOWER ON DELAY BEGINS ON DELAY 10 OR 15 MINUTES STATUS LED HEARTBEAT STATUS LED HEARTBEAT VES GAS VALVE OFF COMBUSTION AIR INDUCER ON INDOOR BLOWER ON STATUS ERROR CODE 5 1 SEQUENCE HOLDS FIRST STAGE LOW FIRE UNTIL ROLLOUT SWITCH IS RESET AND MAIN PRESSURE SWITCH CLOSED POWER IS INTERRUPTED OR THERMOSTAT IS CYCLED OFF ON FOR 3 SECOND MINIMUM GAS VALVE OFF COMBUSTION AIR INDUCER OFF INDOOR BLOWER ON STATUS ERROR CODE 3 1 GAS VALVE OFF COMBUSTION AIR INDUCER HAS PRIMARY OR SECONDARY LIMIT ves OFF FOLLOWING POST PURGE SWITCH CLOSED WITHIN 3 MINUTES INDOOR BLOWER OFF WITH DELAY Indoor blower on low speed during 3 minute period STATUS LED PULSE LIMIT SWITCH WATCHGUARD MODE SECOND STAGE BEAT DEMANDERE GAS VALVE OFF COMBUSTION AIR INDUCER OFF INDOOR BLOWER OFF WITH DELAY STATUS ERROR CODE 4 5 IS 60 MINUTE RESET PERIOD COMPLETE SECOND STAGE PRESSURE SWITCH CLOSED ABNORMAL FLASH CODE GAS VALVE OFF COMBUSTION AIR INDUCER ON NOTE IF SECOND STAGE PRESSURE SWITCH INDOOR BLOWER OFF AFTER DELAY WAS ORIGINALLY FOUND CLOSED STATUS ERROR CODE 2 3 CONTROL RESTAR
27. Adjustments 1135 General 5 Sequence of Operation 36 Combustion Dilution amp Ventilation 6 Eco Eon Mn ee eee Setting 9 Planned Service 42 BC 12 Repair Parts List 42 Duct System 6 eee 12 Integrated Control Diagnostic Codes 43 n eter 13 Troubleshooting 44 02 12 506894 01 Ili Unit Dimensions inches mm 1 NOTE 60C and 60D size units that require air volumes over 1800 cfm 850 L s must have one of the following 1 Single side return air with transition to accommodate 20 x 25 x 1 in 508 x 635 x 25 mm cleanable air filter Required to maintain proper air velocity 2 Single side return air with optional Return Air Base 3 Bottom return air 4 Return air from both sides 5 Bottom and one side return air See Blower Performance Tables for additional information FLUE OUTLET Flue outlet may be horizontal but furnace must be vented vertically 3 Optional External Side Return Air Filter Kit is not for use 3 OPTIONAL with the optional Return Air Base EXTERNAL SIDE RETURN AIR FILTER KIT Either Side 1 1 2 88 _ l lt 3 1 8 79 SUPPLY AIR OPENING 23 3 4
28. Category Appliance Vent and Connector Diameter D inches ee mu J sema sms 3 L feet Appliance Input Rating in Thousands of Btu Per Hour a s ww w 77 x w s sw wo w z s s P 191 958 18 x s m 7 m J m t 38 z i 5581558 1397 7 9 2 m J r Ec N ao 9 t N a ee ww NA N NOTE Single appliance venting m zero os lengths are assumed to have no PTT in the vent TT For all other vent configurations the vent system is assumed to have two 90 elbows For each additional 90 elbow or equivalent for example two 45 elbows equal one 90 elbow beyond two the maximum capacity listed in the venting table should be reduced by 10 percent 0 90 x maxi mum listed capacity 39 7 58 3 xw i xs Eme ar 39 7 NA Page 19 TABLE 5 Vent Connector Capacity Type B Double Wall Vents with Type B Double Wall Connectors Serving Two or More Category 1 Appliances Vent and Connector Diameter D inches Connector Rie _ ee 4 s R Appliance Input Rating in Thousands of Btu Per Hour 38 81 wj N S REN e N wo wj j oy BY o 44 40 44 47
29. E The inlet and outlet air openings shall each have a input rating of all equipment in the enclosure If the equipment room free area of at least one square inch 645 mm2 per 4 000 is located against an outside wall and the air openings communi Btu 1 17 kW per hour of the total input rating of all equip cate directly with the outdoors each opening shall have a free area ment in the enclosure of at least one square inch 645 mm2 per 4 000 Btu 1 17 kW per hour of the total input rating of all other equipment in the enclosure FIGURE 5 FIGURE 6 Page 8 AWARNING Do not install the furnace on its front or its back Do not connect the return air ducts to the back of the fur nace Doing so will adversely affect the operation of the safety control devices which could result in per sonal injury or death The EL280UH gas furnace can be installed as shipped in either the upflow position or the horizontal position Select alocation that allows for the required clearances that are listed on the unit nameplate Also consider gas supply connections electrical supply vent connection and installation and service clearances 24 inches 610 mm at unit front The unit must be level NOTE Units with 1 2 hp blower motors are equipped with three flexible legs and one rigid leg See figure 7 The rigid leg is equipped with a shipping bolt and a flat white plastic washer rather than the rubber mounting grommet used with a flexible mounting leg
30. ESD Precautions and Procedures CAUTION Electrostatic discharge can affect elec tronic components Take precautions to neutralize electrostatic charge by touching your hand and tools to metal prior to handling the control The unit is equipped with a field make up box on the left hand side of the cabinet The make up box may be moved to the right side of the furnace to facilitate installation If the make up box is moved to the right side clip the wire ties that bundle the wires together The excess wire must be pulled into the blower compartment Secure the excess wire to the existing harness to protect it from damage INTERIOR MAKE UP BOX INSTALLATION Right Side FIGURE 29 INTERIOR MAKE UP BOX INSTALLATION Left side FIGURE 30 Refer to figure 31 for schematic wiring diagram and trou bleshooting and table 10 and figure 32 for field wiring The power supply wiring must meet Class restrictions Protected by either a fuse or circuit breaker select circuit protection and wire size according to unit nameplate NOTE Unit nameplate states maximum current draw Maximum over current protection allowed is 15 AMP Holes are on both sides of the furnace cabinet to facilitate wiring Install a separate properly sized disconnect switch near the furnace so that power can be turned off for servicing Page 25 Before connecting the thermostat check to
31. G AWARNING Do not use this furnace if any part has been under water A flood damaged furnace is extremely dan gerous Attempts to use the furnace can result in fire or explosion Immediately call a qualified ser vice technician to inspect the furnace and to replace all gas controls control system parts and electrical parts that have been wet or to replace the furnace if deemed necessary AWARNING If overheating occurs or if gas supply fails to shut off shut off the manual gas valve to the appliance before shutting off electrical supply ACAUTION Before attempting to perform any service or mainte nance turn the electrical power to unit OFF at dis connect switch BEFORE LIGHTING smell all around the appliance area for gas Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor The gas valve on the EL280UH unit will be equipped with a gas control switch Use only your hand to move the switch Never use tools If the switch will not turn or if the control switch will not move by hand do not try to repair it Placing the furnace into operation EL280UH units are equipped with an automatic ignition system Do not attempt to manually light burners on these furnaces Each time the thermostat calls for heat the burners will automatically light The ignitor does not get hot when there is no call for heat on units with an automatic ignition system AWARNING If you do no
32. Installation and service must be performed by a licensed professional installer or equivalent service agency or the gas supplier ACAUTION As with any mechanical equipment personal injury can result from contact with sharp sheet metal edges Be careful when you handle this equipment Certifications EL280UH units are CSA International certified to ANSI Z21 47 In the USA installation of gas furnaces must conform with local building codes In the absence of local codes units must be installed according to the current National Fuel Gas Code ANSI Z223 1 The National Fuel Gas Code is available from the following address American National Standards Institute Inc 11 West 42nd Street New York NY 10036 Clearances Adequate clearance must be made around the air open ings into the vestibule area In order to ensure proper unit operation combustion and ventilation air supply must be provided according to the current National Fuel Gas Code Vent installations must be consistent with the venting tables in this instruction and applicable provisions of local building codes This furnace is CSA International certified for installation clearances to combustible material as listed on the unit nameplate and in the tables in figures 8 and 12 Accessibility and service clearances must take precedence over fire protection clearances NOTE For installation on combustible floors the furnace shall not be installed directly on carpetin
33. LENNOX 2012 Lennox Industries Inc Dallas Texas USA AIR FLOW UPFLOW AIR FLOW INSTALLATION INSTRUCTIONS EL280UH ELITE SERIES GAS FURNACE UPFLOW HORIZONTAL AIR DISCHARGE 506894 01 Technical 02 2012 Publications Litho U S A THIS MANUAL MUST BE LEFT WITH THE HOMEOWNER FOR FUTURE REFERENCE This is a safety alert symbol and should never be ignored When you see this symbol on labels or in manuals be alert to the potential for personal injury or death AWARNING Improper installation adjustment alteration service maintenance can cause property damage al injury or loss of life Installation and service must be performed by a licensed professional installer or equivalent service agency or the gas supplier ACAUTION As with any mechanical equipment personal injury can result from contact with sharp sheet metal edges Be careful when you handle this equipment Table of Contents Unit Dimensions 2 EG TET 22 Parts Arrangement 3 eee eo EL280UH Gas Fumace E 32 Shipping and Packing List 4 Gas Pressure Adjustment 33 Safety Information 4 High ae ee ee n Use of Furnace as a Construction Heater 5 Other Unit
34. LOWER OFF UNIT WILL RETRY AFTER 5 MINUTE WAIT PERIOD STATUS ERROR CODE 2 3 LOW AND HIGH PRESSURE SWITCH CLOSED WITHIN 30 SECONDS OMBUSTION AIR INDUCER NERGIZED ON HIGH SPEED COMBUSTION AIR INDUCER OFF IGNITOR OFF SIGNAL HOLDS UNTIL IGNITOR IS REPLACED OR RECONNECTED STATUS ERROR CODE 4 7 IS VOLTAGE ABOVE 90 VOLTS COMBUSTION AIR INDUCER OFF IGNITOR OFF SIGNAL HOLDS UNTIL VOLTAGE RISES ABOVE 95 VOLTS STATUS ERROR CODE 4 8 GAS VALVE OFF COMBUSTION AIR INDUCER ON INDOOR BLOWER OFF STATUS LED HEARTBEAT HAS CONTROL FAILED TO SENSE FLAME FOR FIVE CONSECUTIVE TRIES DURING A SINGLE HEAT DEMAND WATCHGUARD MODE GAS VALVE OFF COMBUSTION AIR INDUCER OFF INDOOR BLOWER OFF STATUS ERROR CODE 4 1 IS 60 MINUTE RESET PERIOD COMPLETE HAS CONTROL RESET IGNITION SEQUENCE FOUR 4 TIMES WATCHGUARD MODE STATUS ERROR CODE 4 3 If the furnace is operating on continuous fan mode terminals R and G are energized the combustion air inducer will energize on high speed the gas valve will energize on second stage heat and the furnace will operate on high fire Furnace will stay on high fire 60 seconds then switch to low fire If combustion air inducer is operating on high speed and gas valve is energized on second stage heat 20 seconds after flame is sensed furnace will switch to low fire Page 45 Troubleshooting Heating Sequence of Operation Continued HEATING SEQUENCE OF OPER
35. MARY COMBUSTION AIR Lom GAS 84 INDUCER MOTOR GAS LMT ER VALVE BURNERS e me 128 LINE VOLTAGE FIELD INSTALLED IGNITOR S47 LOW HEAT CLASS Il VOLTAGE FIELD WIRING FLAME FLAME PRESSURE ROLLOUT ROLLOUT SWITCH SWITCH SWITCH A USE COPPER CONDUCTORS ONLY 1 ROOM THERMOSTAT ONONO OA HEAT OFF T STAT HEAT STG m 2ND STG DELAY RELAY a S21 A92 SECONDARY INTEGRATED LIMIT CONTROL COOL OFF DELAY c CIRCUIT BREAKER CAPACITOR INDOOR BLOWER MOTOR FIGURE 32 TWO STAGE INTEGRATED CONTROL 1 4 QUICK CONNECT TERMINALS HUM 120 VAC OUTPUT TO HUMIDIFIER EAC 120 VAC OUTPUT TO ELECTRONIC AIR CLEANER XMFR 120 VAC OUTPUT TO TRANSFORMER LI 120 VAC INPUT TO CONTROL SENSE 120 VAC OUTPUT TO FLAME SENSOR NEUTRALS NEUTRALS 120 VAC NEUTRAL PARK DEAD TERMINAL FOR UNUSED BLOWER LEAD HEAT LOW 120 VAC OUTPUT TO CIRC BLWR LOW HT SPEED STATUS HEAT HIGH COOL LOW 120 VAC OUTPUT TO CIRC BLWR N HIGH HEAT AND LOW COOL SPEED COOL HIGH 120 VAC OUTPUT TO CIRC BLWR HIGH COOL SPEED DIAGNOSTIC LED x THERMOSTAT CONNECTIONS TB1 HEAT DEMAND FROM IST STAGE T STAT HEAT DEMAND FROM 2ND STAGE T STAT MANUAL FAN FROM T STAT THERMOSTAT 2nd STAGE COOL SIGNAL THERMOSTAT Ist STAGE COOL SIGNAL THERMOSTAT SIGNAL GROUND CONNECTED TO TRANSFORMER GROUND TR amp CHASIS GROUND GRD ON BOARD R CLASS 2 VOLTAGE TO THERMOSTAT LINKS 1
36. NPT Plugged Tap Shown GROUND JOINT UNION he DRIP LEG Right Side Piping Alternate Horizontal Application Left Side Air Discharge MANUAL MAIN SHUT OFF 27 VALVE GROUND JOINT UNION T DRIP LEG Leak Check After gas piping is completed carefully check all piping connections factory and field installed for gas leaks Use a leak detecting solution or other preferred means NOTE If emergency shutoff is necessary shut off the main manual gas valve and disconnect the main power to the furnace The installer should properly label these devices ACAUTION Some soaps used leak detection corrosive to certain metals Carefully rinse piping thoroughly af ter leak test has been completed Do not use matches candles flame or other sources of ignition to check for gas leaks The furnace must be isolated by closing its individual manual shut off valve and disconnecting from from the gas supply system the during any pressure testing of the gas supply system at pressures greater than 1 2 psig 3 48 kPa 14 inches w c AIMPORTANT When testing pressure of gas lines gas valve must be disconnected and isolated See figure 28 Gas valves can be damaged if subjected to pressures greater than 1 2 psig 3 48 kPa 14 inches w c MANUAL MAIN SHUT OFF VALVE WILL NOT HOLD NORMAL TEST PRESSURE 1 8 NPT PLUG ISOLATE GAS VALVE FURNACE FIGURE 28 ELECTROSTATIC DISCHARGE
37. ORE THAN ONE MOTOR LEAD TO ANY ONE CONNECTION TERMINAL 1 IS USED FOR ERROR CODE RECALLAWLRARK TERMINAL IS A UNPOWERED TERMINAL 51 SEE INSTALLATION INSTRUCTIONS FOR DETAILS ALL UNUSED MOTOR LEADS MUST BE WIRED st DOOR A92 A TO THE PARK TERMINAL 24V POWER IS PROVIDED FOR OPTIONAL TWO STAGE INTERLOCK a INTEGRATED CONTROL HUMIDIFIER DURING HEAT DEMAND USE COPPER CONDUCTORS ONLY HEAT COOL L1 2 LINE XFMR 1 TERMINAL BOARD FLAME SENSE 0005 BURNER ASSY GNI J159 128 LOW HEAT PRESSURE SWITCH SEE BLOWER SPEED CHART INTEGRATED CONTROL COMBUSTION AIR INDUCER MOTOR 102 HIGH HEAT LINE VOLTAGE FIELD INSTALLED CLASS II VOLTAGE FIELD WIRING P84 P159 DENOTES OPTIONAL COMPONENTS A92 INTEGRATED J156 4 156 25 CONTROL S Pis 1 C PRI I I INDOOR BLOWER MOTOR WARNING ELECTRIC SHOCK HAZARD CAN CAUSE INJURY OR DEATH UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND LOCAL CODES J159 HUMIDIFIER PRESSURE SWITCH WHITE COMMON I I I I L J NOTE ga IF ANY WIRE IN THIS APPLIANCE IS REPLACED IT MUST BE REPLACED WITH WIRE OF LIKE SIZE EQUIPMENT RATING INSULATION THICKNESS AND TERMINATION GROUND TYPICAL SYSTEM SHOWN FOR 2 HEAT 2 COOL WITH A CONVENTIONAL THERMOSTAT SEE INSTALLATION INSTRUCTIONS FOR CONNECTION TO OTHER EQUIPMENT AND ACCESSORIES FIGURE 31 Page 29 TYPICAL EL280UH FIELD WIRING DIAGRAM S10 PRI
38. R SECOND STAGE COOL INDOOR BLOWER RAMPS UP TO SECOND STAGE COOL SPEED SECOND STAGE DEMAND FOR COOL SATISFIED YES UNIT RETURNS TO FIRST STAGE COOL Page 48 Troubleshooting Continuous Fan Sequence of Operation CONTINUOUS LOW SPEED FAN SEQUENCE OF OPERATION MANUAL FAN SELECTION MADE AT THERMOSTAT AFTER 2 SECOND DELAY INDOOR BLOWER IS ENERGIZED ON CONTINUOUS FAN SPEED YES YES THERMOSTAT CALLS FOR FIRST STAGE COOL THERMOSTAT CALLS FOR FIRST STAGE HEAT YES YES INDOOR BLOWER RAMPS TO FIRST STAGE AFTER 45 SECOND DELAY INDOOR BLOWER COOLING SPEED AFTER A 2 SECOND DELAY SWITCHES TO LOW HEAT SPEED FIRST STAGE COOL DEMAND SATISFIED FIRST STAGE HEAT DEMAND SATISFIED YE YES SECOND STAGE COOL DEMAND THERMOSTAT CALLS FOR SECOND STAGE HEAT YES INDOOR BLOWER RAMPS TO SECOND INDOOR BLOWER SWITCHES TO HIGH HEAT SPEED STAGE COOL SPEED AFTER 30 SECOND RECOGNITION PERIOD S YES SECOND STAGE COOL DEMAND SATISFIED SECOND STAGE HEAT DEMAND SATISFIED YES YES INDOOR BLOWER RAMPS DOWN TO FIRST STAGE INDOOR BLOWER RAMPS DOWN TO LOW COOL SPEED HEAT SPEED Page 49 Start Up amp Performance Check List UNIT SET UP typical Unit Model Number Serial Number LJ LJ LJ LJ G LJ LJ LJ LJ GAS SUPPLY Natural Gas LP Propane Gas Piping Connections Tight Leak Tested Supply Line Pressure W C VENT EXHAUST
39. RFORMANCE Less Filter EL280UH090P48B PERFORMANCE Less Filter External Air Volume Watts at Various Blower Speeds Static High Medium Low Pressure in w g cfm Watts cfm Watts cfm Watts 0 10 1435 439 990 369 845 299 0 20 1115 429 975 358 820 289 0 30 1085 410 955 348 790 279 0 40 1045 389 925 335 775 270 0 50 1015 374 885 321 735 260 0 60 965 358 835 307 700 248 0 70 890 995 780 289 635 232 0 80 810 315 700 268 560 214 NOTES air data is measured external to unit without filter not furnished field provided EL280UH070P36A PERFORMANCE Less Filter External Air Volume Watts at Various Blower Speeds Static Medium Medium Pressure Fan High Low M in w g cfm Watts cfm Watts cfm Watts cfm Watts 0 10 1620 658 1365 568 1115 468 945 374 0 20 1580 621 1355 535 1135 442 960 362 0 30 1520 595 1335 513 1130 423 955 350 0 40 1480 562 1300 478 1100 403 945 335 0 50 1400 520 1270 450 1080 382 925 320 0 60 1340 490 1205 420 1035 358 880 301 0 70 1245 458 1125 393 975 333 835 282 0 80 1160 434 1045 364 915 310 775 262 NOTES All air data is measured external to unit without filter not furnished field provided EL280UH090P36B PERFORMANCE Less Filter External Ai
40. TAGE THERMOSTAT MODE DIP SWITCH SET AT TWO SECOND STAGE HEAT GAS VALVE OFF COMBUSTION AIR FIRST AND SECOND STAGE HEAT DEMAND SATISFIED INDUCER OFF AFTER 5 SECOND DEMAND SATISFIED SIMULTANEOUSLY STATUS LED HEARTBEAT LOW SPEED POST PURGE PERIOD STATUS LED HEARTBEAT INDOOR BLOWER OFF DELAY INITIATED ON LOW HEAT SPEED STATUS LED HEARTBEAT GAS VALVE COMBUSTION AIR INDUCER AND INDOOR BLOWER RETURN TO FIRST STAGE OPERATION STATUS LED HEARTBEAT FIRST STAGE HEAT DEMAND SATISFIED DEMAND FOR HEAT SATISFIED GAS VALVE OFF COMBUSTION AIR INDUCER POWER ON STAND BY OFF AFTER 5 SECOND LOW SPEED POST PURGE PERIOD INDOOR BLOWER OFF BIIMSEEDSIPHESE DELAY INITIATED ON LOW HEAT SPEED STATUS LED PULSE Page 47 Troubleshooting Cooling Sequence of Operation COOLING SEQUENCE OF OPERATION POWER ON SIGNAL POLARITY REVERSED CIS POLARITYREVERSED ______ CONTROL WILL vr ee SOW OR GOSLING IS POLARITY REVERSED IN THIS CONDITION STATUS ERROR CODE 5 4 SIGNAL IMPROPER GROUND AT LED IS THERE CONTROL WILL CONTINUE TO CALL FOR COOLING PROPER GROUND IN THIS CONDITION STATUS ERROR CODE 5 3 THERMOSTAT CALLS FOR FIRST STAGE COOL COMPRESSOR AND CONDENSER FAN ENERGIZED INDOOR BLOWER ENERGIZED ON FIRST STAGE COOL SPEED AFTER 2 SECOND DELAY YES COMPRESSOR AND CONDENSER FAN DE ENERGIZED FIRST STAGE DEMAND FOR COOL SATISFIED INDOOR BLOWER NO THERMOSTAT CALLS FO
41. TS ABNORMAL CODE WILL FLASH IGNITION SEQUENCE IF PRESSURE SWITCH CLOSES WITHIN 2 1 2 MINUTES SECOND STAGE PRESSURE SWITCH CLOSED SECOND STAGE 30 SECOND DELAY ON BEGINS AT BEGINNING OF HEAT DEMAND STATUS LED HEARTBEAT STATUS ERROR CODE 2 6 SECOND STAGE HEAT DEMAND SECOND STAGE COMBUSTION AIR INDUCER STATUS LED HEARTBEAT ON SECOND STAGE GAS VALVE ON HIGH HEAT INDOOR BLOWER SPEED ON STATUS LED HEARTBEAT RETURNS TO FIRST STAGE HEAT MODE WHICH CONTINUES UNTIL SECOND STAGE PRESSURE SWITCH CAN BE PROVEN or HEAT DEMAND IS SATISFIED FIVE 5 MINUTE WAIT PERIOD SECOND STAGE PRESSURE SWITCH CLOSED INITIATED BEFORE RETRY WERE 5 ATTEMPTS IN LESS THAN TEN 10 SECONDS MADE FOR SECOND STAGE HEAT STATUS LED HEARTBEAT CONTINUES FIRST STAGE HEATING DEMAND WILL NOT REATTEMPT SECOND STAGE CONTINUED ON NEXT PAGE HEATING DEMAND STATUS ERROR CODE 2 5 Page 46 Troubleshooting Heating Sequence of Operation Continued HEATING SEQUENCE OF OPERATION CONTINUED SEE BOX A NORMAL OPERATION SEE BOX B THERMOSTAT CALLS FOR HEAT RETURN TO FIRST STAGE HEAT MODE FIRST STAGE CONTINUES UNTIL SECOND SECOND STAGE HIGH FIRE HEAT STAGE PRESSURE SWITCH CAN BE PROVEN PRESSURE SWITCH CLOSED or HEAT DEMAND IS SATISFIED A FIVE 5 MINUTE WAIT PERIOD IS INITIATED BEFORE RETRY WERE 5 ATTEMPTS MADE FOR SECOND STAGE HEAT HEAT DEMAND SATISFIED NO STATUS LED HEARTBEAT SEE BOX C FIRST STAGE HEAT DEMAND SATISFIED TWO S
42. VE OFF COMBUSTION AIR INDUCER OFF INDOOR BLOWER OFF CONTROL WILL NOT ATTEMPT SECOND STAGE OPERATION DURING THIS HEAT DEMAND FIRST STAGE OPERATION WILL BE ATTEMPTED STATUS ERROR CODE 2 6 Af the furnace is operating on continuous fan mode terminals R and G are energized the combustion air inducer will energize on high speed the gas valve will energize on second stage heat and the furnace will operate on high fire Furnace will stay on high fire 60 seconds then switch to low fire Page 44 Troubleshooting Heating Sequence of Operation Continued HEATING SEQUENCE OF OPERATION CONTINUED FIRST STAGE LOW FIRE PRESSURE SWITCH CLOSED WITHIN 2 0 MINUTES YES 15 SECOND COMBUSTION AIR INDUCER PRE PURGE INITIATED BY CLOSED FIRST STAGE PRESSURE SWITCH or 15 SECOND A INTER PURGE PERIOD STATUS LED HEARTBEAT IGNITOR WARM UP 20 SECONDS STATUS LED HEARTBEAT YES IS IGNITOR INTACT AND CONNECTED A AT END OF IGNITOR 20 SECOND WARM UP PERIOD 4 SECOND TRIAL FOR IGNITION GAS VALVE OPENS IGNITOR ENERGIZED DURING 4 SECOND TRIAL UNTIL FLAME SENSED 4 SECOND FLAME STABILIZATION PERIOD FLAME RECTIFICATION CURRENT CHECK CAN FLAME BE PROVEN WITHIN 4 SECONDS AFTER GAS VALVE OPENS gt 0 20 microamps FLAME PRESENT CONTINUED ON NEXT PAGE THERMOSTAT CALLS FOR HEAT STATUS LED HEARTBEAT Refer to box A on previous page GAS VALVE OFF COMBUSTION AIR INDUCER OFF INDOOR B
43. Watchguard Pressure Switch mode High heat prove switch 5102 may also close 15 second pre purge follows once 5128 closes NOTE If the low fire pressure switch does not close the combustion air inducer will switch to high fire After a 15 second pre purge the high fire pressure switch will close and the unit will begin operation on high fire After 10 to 20 seconds of high fire operation the unit will switch to low fire NOTE If the furnace is operating on continuous fan mode terminal R and G are energized the combustion air in ducer will energize on high speed the gas valve will ener gize on second stage heat and the furnace will operate on high fire Furnace will stay on high fire for 60 seconds then switch to low fire 2 SureLight control begins 20 second ignitor warm up period 3 Gas valve opens on first stage for a 4 second trial for ignition Ignitor stays energized during the trial or until flame sensed 4 Flame is sensed gas valve remains on first stage heat ignitor de energizes 5 After 30 second delay indoor blower B3 is energized on low heat speed 6 A10 minute factory set or 15 minute field set second stage heat delay period begins 7 After the delay the combustion air inducer ramps up to high heat speed 8 102 high heat prove switch closes and the gas valve energizes second stage heat 9 indoor blower switches to high heat speed Page 36 BLOWER DATA EL280UH070P24A PE
44. an dards of the National Fuel Gas Code ANSI Z223 1 Page 22 Gas Piping Gas supply piping should not allow more than 0 5 W C drop in pressure between gas meter and unit Supply gas pipe must not be smaller than unit gas connection ACAUTION If a flexible gas connector is required or allowed by the authority that has jurisdiction black iron pipe shall be installed at the gas valve and extend outside the furnace cabinet The flexible connector can then be added between the black iron pipe and the gas supply line Gas Supply 1 This unit is shipped standard for left or right side instal lation of gas piping or top entry in horizontal applica tions Connect the gas supply to the piping assembly 2 When connecting the gas supply piping consider fac tors such as length of run number of fittings and fur nace rating to avoid excessive pressure drop Table 9 lists recommended pipe sizes for typical applications 3 The gas piping must not run in or through air ducts clothes chutes gas vents or chimneys dumb waiters or elevator shafts 4 The piping should be sloped 1 4 inch 6 4 mm per 15 feet 4 57 m upward toward the meter from the fur nace The piping must be supported at proper intervals every 8 to 10 feet 2 44 to 3 01 m with suitable hang ers or straps Install a drip leg in vertical pipe runs to the unit 5 A 1 8 N P T plugged tap or pressure post is located on the gas valve to facilitate test
45. ansition Make Up Box Collector Box Disconnect pressure switch hose from barbed fitting on the pressure switch assembly Remove pressure switch assembly 1 screw and cut wire tie to free pressure switch wires Re install pressure switch on the other side of orifice plate and re connect pressure switch hose Re secure pressure switch wires by either pulling excess wires through the blower compartment and securing with supplied wire tie or coil excess wire and secure to the gas manifold FIGURE 20 HORIZONTAL RIGHT POSITION Top Vent Discharge on Vent Pipe Flue Transition Pressure Switch T Cover Plate d asp Collector Box Make Up Box Gas supply piping must be brought into the unit from the bottom in order to accommodate the flue pipe Remove make up box assembly 2 screws and cut wire tie to free make up box wires Re install make up box on other side of cabinet Re secure make up box wires by either pulling excess wires through the blower compartment and securing with supplied wire tie or coil excess wire and secure to the gas manifold FIGURE 21 HORIZONTAL RIGHT POSITION Side Vent Discharge Pressure Switch
46. ational Fuel Gas Code ANSI Z223 1 This reprinted material is not the complete and official posi tion of the ANSI on the referenced subject which is repre sented only by the standard in its entirety ACAUTION Do not install the furnace in a corrosive or contami nated atmosphere Meet all combustion and ventila tion air requirements as well as all local codes ACAUTION Insufficient combustion air can cause headaches nausea dizziness or asphyxiation It will also cause excess water in the heat exchanger resulting in rust ing and premature heat exchanger failure Excessive exposure to contaminated combustion air will result in safety and performance related problems Avoid exposure to the following substances in the combus tion air supply Permanent wave solutions Chlorinated waxes and cleaners Chlorine base swimming pool chemicals Water softening chemicals De icing salts or chemicals Carbon tetrachloride Halogen type refrigerants Cleaning solvents such as perchloroethylene Printing inks paint removers varnishes etc Hydrochloric acid Cements and glues Antistatic fabric softeners for clothes dryers Masonry acid washing materials All gas fired appliances require air for the combustion pro cess If sufficient combustion air is not available the fur nace or other appliances will operate inefficiently and un safely Enough air must be provided to meet the needs of all fuel burning appliances and applian
47. cal power to the unit if service is to be performed 3 Remove the upper access panel 4 Move switch on gas valve to OFF Do not force 5 Replace the upper access panel Failure To Operate If the unit fails to operate check the following 1 Is the thermostat calling for heat 2 Are access panels securely in place 3 Is the main disconnect switch closed 4 s there a blown fuse or tripped circuit breaker 5 Is the filter dirty or plugged Dirty or plugged filters will cause the limit control to shut the unit off 6 Is gas turned on at the meter 7 15 the manual main shut off valve open 8 Is the internal manual shut off valve open Page 32 9 Is the unit ignition system in lock out If the unit locks out again call the service technician to inspect the unit for blockages 10 Is pressure switch closed Obstructed flue will cause unit to shut off at pressure switch Check flue and outlet for blockages 11 Are flame rollout switches tripped If flame rollout switches are tripped call the service technician for in spection Gas Pressure Adjustment Gas Flow Approximate TABLE 12 GAS METER CLOCKING CHART Seconds for One Revolution EL280UH Natural Unit 2 cu ft DIAL 90 41 52 102 294 5035 5 27 54 6 136 Natural 1000 btu cu ft LP 2500 btu cu ft Furnace should operate at least 5 minutes before check ing gas flow Determin
48. ces Top Vent Connector 2 1 4 in 57 mm 2 1 4 in 57 Front clearance in alcove installation must be 24 in 610 mm Maintain a minimum of 24 in 610 mm for front service access 4 1 2 in if singlewall vent pipe is used For installations on a combustible floor do not install the furnace directly on carpeting tile or other combustible materials other than wood flooring FIGURE 12 Horizontal Applications The EL280UH furnace can be installed in horizontal ap plications Order horizontal suspension kit 51W10 from Lennox or use equivalent suspension method Allow for clearances to combustible materials as indicated on the unit nameplate Minimum clearances for closet or al cove installations are shown in figure 12 This furnace may be installed in either an attic or a crawl space Either suspend the furnace from roof rafters or floor joists as shown in figure 13 or install the furnace on a platform as shown in figure 14 Typical Horizontal Application Unit Suspended in Attic or Crawlspace Bottom Cap Es 3 16 inch FIGURE 13 NOTE Heavy gauge perforated sheet metal straps may be used to suspend the unit from roof rafters or ceiling joists When straps are used to suspend the unit in this way support must be provided for both the ends The straps must not interfere with the plenum or exhaust pip ing installation Cooling coils and supply and return air plenums must be s
49. ces such as exhaust fans which force air out of the house When fireplaces ex haust fans or clothes dryers are used at the same time as the furnace much more air is necessary to ensure proper combustion and to prevent a downdraft Insufficient air causes incomplete combustion which can result in carbon monoxide In addition to providing combustion air fresh outdoor air dilutes contaminants in the indoor air These contami nants may include bleaches adhesives detergents sol vents and other contaminants which can corrode furnace components The requirements for providing air for combustion and ven tilation depend largely on whether the furnace is installed in an unconfined or a confined space Page 6 Unconfined Space An unconfined space is an area such as a basement or large equipment room with a volume greater than 50 cubic feet 1 42 m3 per 1 000 Btu 29 kW per hour of the com bined input rating of all appliances installed in that space This space also includes adjacent rooms which are not separated by a door Though an area may appear to be un confined it might be necessary to bring in outdoor air for combustion if the structure does not provide enough air by infiltration If the furnace is located in a building of tight construction with weather stripping and caulking around the windows and doors follow the procedures in the air from outside section Confined Space A confined space is an area with a volume less than
50. d check for proper operation 23 Check all piping connections factory and field for gas leaks Use a leak detecting solution or other preferred means A CAUTION Some soaps used leak detection corrosive to certain metals Carefully rinse piping thoroughly af ter leak test has been completed Do not use matches candles flame or other sources of ignition to check for gas leaks 24 If aleak is detected shut gas and electricity off and repair leak 25 Repeat steps 24 and 26 until no leaks are detected 26 Replace access panel Page 41 Planned Service The following items should be checked during an annual inspection Power to the unit must be shut off for the service techni cian s safety Fresh air grilles and louvers on the unit and in the room where the furnace is installed Must be open and unob structed to provide combustion air Burners Must be inspected for rust dirt or signs of water Vent pipe Must be inspected for signs of water damaged or sagging pipe or disconnected joints Unit appearance Must be inspected for rust dirt signs of water burnt or damaged wires or components Blower access panel Must be properly in place and pro vide a seal between the return air and the room where the furnace is installed Return air duct Must be properly attached and provide an air seal to the unit Operating performance Unit must be observed during operation to monito
51. duct system The base must provide a stable support and an airtight seal to the furnace Al low absolutely no sagging cracks gaps etc The return and supply air duct systems must never be connected to or from other heating devices such as a fireplace or stove etc Fire explosion carbon monoxide poisoning personal injury and or proper ty damage could result AWARNING The blower access panel must be securely in place when the blower and burners are operating Gas fumes which could contain carbon monoxide can be drawn into living space resulting in personal inju ry or death This unit is not equipped with a filter or rack A field pro vided high velocity filter is required for the unit to operate properly Table 1 lists recommended filter sizes A filter must be in place any time the unit is operating TABLE 1 Furnace Cabinet Width Side Return Bottom Return A 14 1 2 16 X 25 X1 1 14X25X1 1 B 17 1 2 16X25 X1 1 16X25 X1 1 16X25X1 1 20X25X1 1 D 24 1 2 16 X 25 X 1 2 24 X 25 X 1 1 Duct System Use industry approved standards such as those pub lished by Air Conditioning Contractors of America or Ameri can Society of Heating Refrigerating and Air Conditioning Engineers to size and install the supply and return air duct System This will result in a quiet and low static system that has uniform air distribution NOTE Do not operate the furnace in the heating mode with an external static
52. e time in seconds for two revolu tions of gas through the meter Two revolutions assures a more accurate time Divide by two and compare to time in table 12 below If manifold pressure matches table 14 and rate is incorrect check gas orifices for proper size and restriction Remove temporary gas meter if installed NOTE To obtain accurate reading shut off all other gas appliances connected to meter Supply Pressure Measurement An inlet post located on the gas valve provides access to the supply pressure See figure 34 Back out the 3 32 hex screw one turn connect a piece of 5 16 tubing and con nect to a manometer to measure supply pressure See table 14 for supply line pressure Manifold Pressure A manifold pressure post located on the gas valve provides access to the manifold pressure See figure 34 Back out the 3 32 hex screw one turn connect a piece of 5 16 tubing and connect to a manometer to measure manifold pres sure NOTE Pressure test adapter kit 10L34 is available from Lennox to facilitate manifold pressure measurement 1 Connect test gauge to manifold pressure post figure 34 gas valve 2 Ignite unit on high fire and let run for 5 minutes to allow for steady state conditions 3 After allowing unit to stabilize for 5 minutes record manifold pressure and compare to value given in table 14 4 f necessary make adjustments Figure 34 shows location of high fire adjustment screw 5
53. ecure the combustion air inducer pressure switch assembly to the orifice plate See figure 15 Lift and rotate the as sembly 90 degrees clockwise or counter clockwise to either the 3 o clock position or to 9 o clock position and re secure with four screws Gasket should be left in place Use tin snips to cut preferred opening on the cabinet for repositioning the flue outlet Use the cut out piece as a cover plate to patch unused opening on cabinet UPFLOW POSITION Left Side Vent Discharge Cover Plate iit VA N Collector Box Pressure Switch Make Up Vent Pipe Ju Box Flue Transition AIR FLOW Gas supply piping must be brought into the unit from the right side in order to accommodate the flue pipe Remove make up box assembly 2 screws and cut wire tie to free make up box wires Re install make up box on other side of cabinet Re secure make up box wires either pulling excess wires through the blower compartment and securing with supplied wire tie or coil excess wire and secure to the gas manifold FIGURE 17 UPFLOW POSITION Right Side Vent Discharge Cover Plate u Flue Transition Pressure Switch N Vent Pipe eo Collector NE ESQ Box rf ex S
54. ed to the unit NOTE Do not secure the electrical conduit directly to the air ducts or structure HEAT FAN OFF TIME IN SECONDS 60sec 90sec T 12 345 12 3 4 5 120sec ON ON EUM 1 2 3 45 3 180sec 5 To adjust fan off timing flip dip switch to desired setting FIGURE 35 Electrical 1 Check all wiring for loose connections 2 Check for the correct voltage at the furnace furnace operating Correct voltage is 120VAC 10 3 Check amp draw on the blower motor with inner blow er panel in place Unit Nameplate Blower Speeds Follow the steps below to change the blower speeds 1 Turn off electrical power to furnace 2 Remove blower access panel 3 Disconnect existing speed tap at integrated control speed terminal NOTE Termination of any unused motor leads must be insulated 4 Place unused blower speed tap on integrated control PARK terminal or insulate 5 Refer to blower speed selection chart on unit wiring dia gram for desired heating or cooling speed See Blower performance data beginning on the next page 6 Connect selected speed tap at integrated control speed terminal 7 Resecure blower access panel 8 Turn on electrical power to furnace 9 Recheck temperature rise Electronic Ignition The integrated control has an added feature of a
55. ed or misplaced filters will dam age the unit EL280UH units may be used for heating of buildings or structures under construction if the following conditions are met e The vent system must be permanently installed per these installation instructions e A room thermostat must control the furnace The use of fixed jumpers that will provide continuous heating is not allowed e The return air duct must be provided and sealed to the furnace e Return air temperature range between 60 F 16 C and 80 F 27 C must be maintained Air filters must be installed in the system and must be maintained during construction e Air filters must be replaced upon construction comple tion e The input rate and temperature rise must be set per the furnace rating plate e One hundred percent 10096 outdoor air must be pro vided for combustion air requirements during construc tion Temporary ducting may supply outdoor air to the furnace Do not connect duct directly to the furnace Size the temporary duct following these instructions in section for Combustion Dilution and Ventilation Air in a confined space with air from outside e The furnace heat exchanger components duct system air fillers and evaporator coils must be thoroughly cleaned following final construction clean up e All furnace operating conditions including ignition in put rate temperature rise and venting must be verified according to these installation instructions
56. elbow beyond two the maximum capacity listed in the venting table should be reduced by 10 percent 0 90 x maxi mum listed capacity TABLE 8 Common Vent Capacity Type B Double Wall Vents with Single Wall Metal Connectors Serving Two or More Category 1 Appliances Common Vent Diameter D inches Appliance Input Rating in Thousands of Btu Per Hour Page 21 Removal of the Furnace from Common Vent In the event that an existing furnace is removed from a venting system commonly run with separate gas ap pliances the venting system is likely to be too large to properly vent the remaining attached appliances Conduct the following test while each appliance is operat ing and the other appliances which are not operating re main connected to the common venting system If the venting system has been installed improperly you must correct the system as indicated in the general venting re quirements section A WARNING CARBON MONOXIDE POISONING HAZARD Failure to follow the steps outlined below for each appliance connected to the venting system being placed into operation could result in carbon mon oxide poisoning death The following steps shall be followed for each ap pliance connected to the venting system being placed into operation while all other appliances connected to the venting system are not in operation 1 Sealany unused openings in the common venting sys tem 2 Inspect the venting system for pr
57. ent connector length of 1 1 2 feet 46 m for each inch 25 mm of connector diameter as follows TABLE 2 inches mm Connector Length feet m If the common vertical vent is offset the maximum common vent capacity listed in the common venting tables should be reduced by 20 the equivalent of two 90 elbows 0 80 x maximum common vent capacity The horizontal length of the offset shall not exceed 1 1 2 feet 46 m for each inch 25 mm of common vent diameter 10 The vent pipe should be as short as possible with the least number of elbows and angles required to com plete the job Route the vent connector to the vent us ing the shortest possible route 11 A vent connector shall be supported without any dips or sags and shall slope a minimum of 1 4 inch 6 4 mm per linear foot 305 mm of connector back toward the appliance 12 Vent connectors shall be firmly attached to the furnace flue collar by self drilling screws or other approved means except vent connectors of listed type B vent material which shall be assembled according to the manufacturer s instructions Joints between sections of single wall connector piping shall be fastened by screws or other approved means 13 When the vent connector used for Category ap pliances must be located in or pass through a crawl space attic or other areas which may be cold that por tion of the vent connector shall be constructed of listed double wall type B vent mate
58. ew I oy Make Up Box row BE YS P Pressure switch tubing may be too long Cut to fit then re attach to barbed fitting on pressure switch Tubing must not be allowed to sag FIGURE 18 Page 13 Horizontal Position HORIZONTAL LEFT POSITION Top Vent Discharge Pressure Switch Vent Pipe Co e Flue Transition Cover Plate Make Up Box Collector Box Disconnect pressure switch hose from barbed fitting on the pres sure switch assembly Remove pressure switch assembly 1 Screw and cut wire tie to free pressure switch wires Re install pressure switch on the other side of orifice plate and re connect pressure switch hose Re secure pressure switch wires by either pulling excess wires through the blower compartment and securing with supplied wire tie or coil excess wire and secure to the gas manifold FIGURE 19 HORIZONTAL LEFT POSITION Side Vent Discharge Pressure Switch Flue Tr
59. fire heating mode the indoor blower will run on the cor responding heating speed 3 When the EL280UH is operating in the low cool or the high cool cooling mode the indoor blower will run on the corresponding cooling speed Page 26 Thermostat 1 Heat 1 Cool NOTE Use DIP switch 2 to set sec ond stage heat ON delay OFF10 minutes ON 15 minutes 1 Heat 2 Cool NOTE Use DIP switch 2 to set sec ond stage heat ON delay OFF 10 minutes ON 15 minutes TABLE 10 Field Wiring Applications DIP Switch Settings and On Board Links See figure 33 W915 Two Stage W951 Cooling Heat Pumps Intact Intact Intact Page 27 Wiring Connections CONTROL OUTDOOR TERM STRIP UNIT 51 CONTROL OUTDOOR T STAT TERM STRIP UNIT e 6 TABLE 10 Field Wiring Applications Continued DIP Switch Settings and On Board Links See figure 33 W915 Thermostat Two Stage W951 Wiring Connections Cooling Heat Pumps 2 Heat 2 Cool OFF Cut Intact ae pasqa s ss 2 Heat 1 Cool Intact Intact S1 CONTROL OUTDOOR T STAT TERM STRIP UNIT ea RES Page
60. furnace When servicing controls label all wires prior to dis connecting Take care to reconnect wires correctly Verify proper operation after servicing At the beginning of each heating season a qualified techni cian should check the system as follows Blower Check the blower wheel for debris and clean if necessary The blower motors are prelubricated for extended bearing life No further lubrication is needed AWARNING The blower access panel must be securely in place when the blower and burners are operating Gas fumes which could contain carbon monoxide can be drawn into living space resulting in personal inju ry or death Filters All EL280UH filters are installed external to the unit Filters should be inspected monthly Clean or replace the filters when necessary to ensure that the furnace operates prop erly Replacement filters must be rated for high velocity air flow Table 1 lists recommended filter sizes Flue And Chimney 1 Check flue pipe chimney and all connections for tight ness and to make sure there is no blockage 2 Check unit for proper draft Electrical 1 Check all wiring for loose connections 2 Check for the correct voltage at the furnace furnace operating Correct voltage is 120VAC 10 3 Check amp draw on the blower motor with inner blow er panel in place Unit Nameplate Actual Page 39 Cleaning the Heat Exchanger and Burners 5 NOTE Use papers or pro
61. g tile or other combustible material other than wood flooring Installed Locations For installation in a residential garage the furnace must be installed so that the burner s and the ignition source are located no less than 18 inches 457 mm above the floor The furnace must be located or protected to avoid physical damage by vehicles When a furnace is installed in a public garage hangar or other building that has a haz ardous atmosphere the furnace must be installed accord ing to recommended good practice requirements and cur rent National Fuel Gas Code Temperature Rise NOTE Furnace must be adjusted to obtain a temperature rise within the range specified on the unit nameplate Failure to do so may cause erratic limit operation and may result in premature heat exchanger failure This EL280UH furnace must be installed so that its electri cal components are protected from water Page 4 Installed in Combination with a Cooling Coil When this furnace is used with cooling units it shall be installed in parallel with or on the upstream side of cooling units to avoid condensation in the heating compartment See figure 2 With a parallel flow arrangement a damper or other means to control the flow of air must adequately pre vent chilled air from entering the furnace If the damper is manually operated it must be equipped to prevent operation of either the heating or the cooling unit unless it is in the full HEAT or COOL setti
62. ing system does not meet these re 19 In no case shall the vent connector be sized more than quirements it must be resized TABLE 3 Capacity of Type B Double Wall Vents with Type B Double Wall Connectors Serving a Single Category Appliance Vent and Connector Diameter D inches C r s Appliance Input Rating in Thousands of Btu Per Hour M MAX ui CMN C MAX MN YT MAX JS MN 10 7 J s P s s s 20 x opm 15 3 3 OIN 155 959 L9 112 195 S 520 357 10 28 64 38 133 50 229 62 351 9 89 s m 3 m e z 522 s x 2 J G 2 3 42 sa es n _ r s 26 7 3 m s s s s 3 Co 1 N nn m s 2 4 m w NOTE Single appliance venting configurations with zero lateral lengths are assumed to have no elbows in the vent system For all other vent configurations the vent system is assumed to have two 90 elbows For each additional 90 elbow or equivalent for example two 45 elbows equal one 90 elbow beyond two the maximum capacity listed in the venting table should be reduced by 10 percent 0 90 x maxi mum listed capacity Page 18 TABLE 4 Capacity of Type B Double Wall Vents with Single Wall Metal Connectors Serving a Single
63. l Supply External Static Return External Static Total External Static 6 DRAIN LINE Leak Free THERMOSTAT L Adjusted and Programmed L Operation Explained to Owner Telephone Checklist Completed Technician s Name Page 51
64. minimum free area of 1 square inch 645 mm per 1 000 Btu 29 kW per hour of total input rating of all gas fired equipment in the confined space Each opening must be at least 100 square inches 64516 mm One opening shall be within 12 inches 305 mm of the top of the enclosure and one opening within 12 inches 305 mm of the bottom See figure 3 Air from Outside If air from outside is brought in for combustion and ventila tion the confined space must have two permanent open ings One opening shall be within 12 inches 305 mm of the top of the enclosure and one opening within 12 inches 305 mm of the bottom These openings must communicate di rectly or by ducts with the outdoors or spaces crawl or at tic that freely communicate with the outdoors or indirectly through vertical ducts Each opening shall have a minimum free area of 1 square inch 645 mm per 4 000 Btu 1 17 kW per hour of total input rating of all equipment in the en closure See figures 4 and 5 When communicating with the outdoors through horizontal ducts each opening shall have a minimum free area of 1 square inch 645 mm per 2 000 Btu 56 kW per total input rating of all equipment in the enclosure See figure 6 When ducts are used they shall be of the same cross sec tional area as the free area of the openings to which they connect The minimum dimension of rectangular air ducts shall be no less than 3 inches 75 mm In calculating free area the bl
65. n internal Watchguard control The feature serves as an automatic re set device for integrated control lockout caused by ignition failure This type of lockout is usually due to low gas line pressure After one hour of continuous thermostat demand for heat the Watchguard will break and remake thermostat demand to the furnace and automatically reset the inte grated control to begin the ignition sequence Actual Page 35 Heating Sequence of Operation When there is a call for heat the integrated control runs a self check The control checks for S10 primary limit S21 secondary limit s and S47 rollout switch normally closed contacts The control also checks for S102 high heat and 128 low heat prove switch normally open contacts Once self check is complete and all safety switches are opera tional heat call can continue Two Stage Thermostat Two Stage Heat Dip Switch set at TWO 1 SureLight control energizes combustion air inducer B6 on low heat speed Combustion air inducer runs until S128 low heat prove switch contacts close switch must close within 2 1 2 minutes or control goes into Watchguard Pressure Switch mode High heat prove switch 5102 may also close 15 second pre purge follows once 5128 closes NOTE If the low fire pressure switch does not close the combustion air inducer will switch to high fire After a 15 second pre purge the high fire pressure switch will close and the unit will begin operation on
66. ng See figure 2 Heating Unit Installed Parallel to Cooling Coil Dampers open during heating operation only L Cooling Coil Dampers open during cooling operation only Heating Unit Installed Upstream of Cooling Unit FE Cooling Coil FIGURE 2 When installed this furnace must be electrically grounded according to local codes In addition in the United States installation must conform with the current National Elec tric Code ANSI NFPA No 70 The National Electric Code ANSI NFPA No 70 is available from the following ad dress National Fire Protection Association 1 Battery March Park Quincy MA 02269 NOTE This furnace is designed for a minimum continu ous return air temperature of 60 F 16 C or an intermit tent operation down to 55 F 13 C dry bulb for cases where a night setback thermostat is used Return air tem perature must not exceed 85 F 29 C dry bulb The EL280UH furnace may be installed in alcoves closets attics basements garages crawl spaces and utility rooms in the upflow or horizontal position This furnace design has not been CSA International certified for installation in mobile homes recreational vehicles or outdoors Use of Furnace as Construction Heater Lennox does not recommend the use of EL280UH units as a construction heater during any phase of construction Very low return air temperatures harmful vapors and op eration of the unit with clogg
67. ntrol failed self check internal error control will restart if error recovers No Earth ground control will restart if error recovers Reversed line voltage polarity control will restart if the error recovers Low secondary 24VAC voltage Error Code Storage 5 After final error code is indicated STATUS LED will The ignition control stores the last ten error codes in flash to indicate normal operation memory The codes are retained in case of power loss Clearing Error Codes Error Code Review 1 Short R 2 to 1 Within 1 2 second the STATUS LED 1 Short R 2 to 1 Within 1 2 second the STATUS LED will stay lit continuously to indicate that the short was will stay lit continuously to indicate that the short was sensed sensed 2 Continue to hold the short between R 2 to 1 After 5 2 Continue to hold the short between R 2 to 1 After 5 seconds STATUS LED will go from being continuously seconds STATUS LED will go from being continuously lit to off lit to off This indicates that error code review is pend 3 Continue to hold the short between R 2 to 1 beyond ing ten seconds after STATUS LED has turned off STA 3 Remove R 2 to 1 short within ten seconds of STA TUS LED will turn on indicating that error codes have TUS LED turning off This activates error code review been cleared 4 Last ten error codes will be flashed on the STATUS 4 Remove R 2 to 1 short STATUS LED will flash to in LED dicate no
68. ocking effect of louvers grilles or screens must be considered If the design and free area of protective cov ering is not known for calculating the size opening required it may be assumed that wood louvers will have 20 to 25 per cent free area and metal louvers and grilles will have 60 to 75 percent free area Louvers and grilles must be fixed in the open position or interlocked with the equipment so that they are opened automatically during equipment operation Page 7 EQUIPMENT IN CONFINED SPACE ALL AIR FROM OUTSIDE Inlet Air from Crawlspace and Outlet Air to Ventilated Attic CHIMNEY OR GAS VENT VENTILATION LOUVERS Each end of attic FURNACE AIR WATER HEATER VENTILATION LOUVERS For unheated crawl space NOTE The inlet and outlet air openings shall each have a free area of at least one square inch 645 mm per 4 000 Btu 1 17 kW per hour of the total input rating of all equipment in the enclosure FIGURE 4 EQUIPMENT IN EQUIPMENT IN CONFINED SPACE CONFINED SPACE ALL AIR FROM OUTSIDE ALL AIR FROM CHIMNEY All Air Through Ventilated Attic OUTSIDE OR GAS WATER VENTILATION LOUVERS HEATER Each end of attic lll dub dj OUTLET AIR FURNACE FURNACE INLET AIR Ends 12 in rl above bottom INLET AIR WATER HEATER Str tt te te th NOTE Each air duct opening shall have a free area of at least one square inch 645 mm per 2 000 Btu 59 kW per hour of the total NOT
69. oper size and horizontal pitch Determine that there is no blockage restriction leakage corrosion or other deficiencies which could cause an unsafe condition 3 Close all building doors and windows and all doors be tween the space in which the appliances remaining connected to the common venting system are located and other spaces of the building Turn on clothes dry ers and any appliances not connected to the common venting system Turn on any exhaust fans such as range hoods and bathroom exhausts so they will oper ate at maximum speed Do not operate a summer ex haust fan Close fireplace dampers 4 Follow the lighting instructions Turn on the appliance that is being inspected Adjust the thermostat so that the appliance operates continuously 5 After the burner have operated for 5 minutes test for leaks of flue gases at the draft hood relief opening Use the flame of a match or candle 6 After determining that each appliance connected to the common venting system is venting properly step 3 return all doors widows exhaust fans fireplace damp ers and any other gas burning appliances to their pre vious mode of operation If a venting problem is found during any of the preced ing tests the common venting system must be modi fied to correct the problem N Resize the common venting system to the minimum vent pipe size determined by using the appropriate tables in Appendix G These are in the current st
70. or Blower and Motor Assembly removed from cabinet FIGURE 1 Page 3 EL280UH Gas Furnace The EL280UH unit is shipped ready for installation in the upflow or horizontal right position for horizontal left posi tion the combustion air pressure switch must be moved The furnace is shipped with the bottom panel in place The bottom panel must be removed if the unit is to be installed in a horizontal application The panel may also be re moved in upflow applications Shipping and Packing List Package 1 of 1 contains 1 Assembled EL280UH unit 1 Bag assembly containing the following 2 Screws 1 Snap bushing 1 Snap plug 1 Wire tie 1 Vent warning label 1 Owner s manual and warranty card The following items may be ordered separately 1 Thermostat 1 Suspension kit for horizontal installations 1 Propane LP changeover kit 1 Return air base 1 High altitude kit 1 Side filter kit Check equipment for shipping damage If you find any damage immediately contact the last carrier DANGER Danger of explosion There are circumstances in which odorant used with LP propane gas can lose its scent In case of a leak LP propane gas will settle close to the floor and may be difficult to smell An LP propane leak detector should be installed in all LP applications AWARNING Improper installation adjustment alteration service or maintenance can cause property damage person al injury or loss of life
71. ornia to cause cancer Fiberglass wool may also cause respiratory skin and eye irritation To reduce exposure to this substance or for further information consult material safety data sheets available from address shown below or contact your supervisor Lennox Industries Inc P O Box 799900 Dallas TX 75379 9900 Combustion Dilution amp Ventilation Air In the past there was no problem in bringing in sufficient out door air for combustion Infiltration provided all the air that was needed In today s homes tight construction practices make it necessary to bring in air from outside for combus tion Take into account that exhaust fans appliance vents chimneys and fireplaces force additional air that could be used for combustion out of the house Unless outside air is brought into the house for combustion negative pressure outside pressure is greater than inside pressure will build to the point that a downdraft can occur in the furnace vent pipe or chimney As a result combustion gases enter the liv ing space creating a potentially dangerous situation In the absence of local codes concerning air for combus tion and ventilation use the guidelines and procedures in this section to install EL280UH furnaces to ensure efficient and safe operation You must consider combustion air needs and requirements for exhaust vents and gas piping A portion of this information has been reprinted with per mission from the N
72. ot exceed 7 times the smallest listed appliance categorized vent area drafthood outlet area or flue collar area unless de signed according to approved engineering methods Page 16 6 Common Venting Using Tile Lined Interior Masonry Chimney and Combined Vent Connector 7 MINIMUM LENGTH AS SHORT AS PRACTICAL INTERIOR TILE LINED FOR MAXIMUM LENGTH SEE NOTE TO LEFT MASONRY CHIMNEY NOTE Refer to provided venting g r tables for installations NOTE the chimney must be properly OTHER APPLIANCE FURNACE sized per provided venting tables or lined with listed metal lining system VENT eee CONNECTOR PERMANENTLY SEALED FIREPLACE OPENING FIGURE 25 The entire length of single wall metal vent connector shall be readily accessible for inspection cleaning and replacement Single appliance venting configurations with zero lat eral lengths tables 3 and 4 are assumed to have no elbows in the vent system For all other vent configura tions the vent system is assumed to have two 90 el bows For each additional 90 elbow or equivalent for example two 45 elbows equal one 90 elbow beyond two the maximum capacity listed in the venting table should be reduced by 10 0 90 x maximum listed ca pacity The common venting tables 5 6 7 and 8 were gen erated using a maximum horizontal v
73. r Volume Watts at Various Blower Speeds Static Medium Medium Pressure High High Low Low in w g cfm Watts cfm Watts cfm Watts cfm Watts 0 10 1760 730 1435 576 1185 452 970 378 0 20 1725 683 1420 547 1170 440 975 368 0 30 1685 656 1410 525 1170 420 980 356 0 40 1630 625 1370 501 1150 400 955 340 0 50 1535 569 1315 469 1125 391 925 326 0 60 1470 533 1275 440 1085 367 910 309 0 70 1365 490 1185 407 1020 344 840 290 0 80 1255 466 1105 380 935 314 785 266 NOTES air data is measured external to unit without filter not furnished field provided External Air Volume Watts at Various Blower Speeds Static Medium Medium Pressure High High Low Low in w g cfm Watts cfm Watts cfm Watts cfm Watts 0 10 2030 804 1780 719 1525 613 1280 518 0 20 1910 740 1740 666 1535 580 1305 493 0 30 1840 698 1705 643 1500 551 1305 474 0 40 1770 664 1635 594 1460 517 1280 445 0 50 1665 625 1560 567 1410 483 1225 420 0 60 1585 595 1470 523 1330 451 1190 391 0 70 1470 561 1365 483 1260 421 1115 368 0 80 1355 514 1230 433 1155 392 1020 338 NOTES All air data is measured external to unit without filter not furnished field provided EL280UH110P48C PERFORMANCE Less Filter
74. r connect a Category appliance to a chimney that is servicing a solid fuel appliance If a fireplace chimney flue is used to vent this appliance the fireplace opening must be permanently sealed A type B or listed chimney lining system that passes through an unused masonry chimney flue is not considered to be exposed to the outdoors General Venting Requirements Vent all EL280UH furnaces according to these instructions 1 Vent diameter recommendations and maximum allow able piping runs are found in the provided venting tables 2 In no case should the vent or vent connector diameter be less than the diameter specified in the provided venting tables 3 The minimum vent capacity determined by the sizing tables must be less than the low fire input rating and the maximum vent capacity must be greater than the high fire input rating 4 Single appliance vents If the vertical vent or tile lined chimney has a larger diameter or flow area than the vent connector use the vertical vent diameter to de termine the minimum vent capacity and the vent connector diameter to determine the maximum vent capacity The flow area of the vertical vent however shall not exceed 7 times the flow area of the listed ap pliance categorized vent area drafthood outlet area or flue collar area unless designed according to approved engineering methods 5 Multiple appliance vents The flow area of the largest section of vertical vent or chimney shall n
75. r proper performance of the unit and the vent system Combustion gases Flue products must be analyzed and compared to the unit specifications Problems detected during the inspection may make it nec essary to temporarily shut down the furnace until the items can be repaired or replaced Instruct the homeowners to pay attention to their furnace Situations can arise between annual furnace in spections that may result in unsafe operation For instance items innocently stored next to the furnace may obstruct the combustion air supply This could cause incomplete combustion and the production of carbon monoxide gas Repair Parts List The following repair parts are available through independent Lennox dealers When ordering parts include the complete furnace model number listed on the CSA International nameplate Example EL280UH070P24A 01 All service must be performed by a licensed professional installer or equivalent service agency or gas supplier Cabinet Parts Main access panel Blower panel Top cap Control Panel Parts Transformer Integrated control Door interlock switch Circuit breaker Blower Parts Blower wheel Blower housing Motor Motor mounting frame Motor capacitor Blower housing cutoff plate Heating Parts Flame sensor Heat exchanger assembly Gas manifold Combustion air inducer Gas valve Main burner cluster Main burner orifices Pressure switch Ignitor Primary limit control Flame rollout switch s
76. res Table 11 pro vides the blower off timings that will result from different switch settings TABLE 11 Heating Blower Off Delay Switch Settings Blower Off Delay Switch 3 Seconds i 90 120 O 1800 O Switch 5 Cooling Blower Off Delay The cooling blower off delay time that the blower operates after the cooling demand has been satisfied can be adjusted by moving switch 5 on the integrated control The switch is fac tory set in the OFF position which provides a cooling blow er off delay of 45 seconds If the switch is toggled to the ON position it will provide a 2 second cooling blower off delay On Board Link W951 Heat Pump R to O On board link W951 is a clippable connection between ter minals R and O on the integrated control W951 must be cut when the furnace is installed in applications which include a heat pump unit and a thermostat which features dual fuel use If the link is left intact terminal O will remain ener gized eliminating the HEAT MODE in the heat pump On Board Link W915 2 Stage Compr Y1 to Y2 On board link W915 is a clippable connection between ter minals Y1 and Y2 on the integrated control W915 must be cut if two stage cooling will be used If the link is not cut the outdoor unit will operate in second stage cooling only and the indoor blower will operate on high cool speed only Page 31 Unit Start Up FOR YOUR SAFETY READ BEFORE LIGHTIN
77. rial or material having equivalent insulation qualities 14 All venting pipe passing through floors walls and ceil ings must be installed with the listed clearance to com bustible materials and be fire stopped according to lo cal codes In absence of local codes refer to NFGC 2223 1 15 No portion of the venting system extend into pass through any circulation air duct or plenum Page 17 16 Vent connectors serving Category appliances shall two consecutive table size diameters over the size of not be connected to any portion of mechanical draft the draft hood outlet or flue collar outlet systems operating under positive pressure such as 20 Do not install a manual damper barometric draft regu Category III or IV venting systems lator or flue restrictor between the furnace and the 17 If vent connectors are combined prior to entering the chimney common vent the maximum common vent capacity 21 When connecting this appliance to an existing dedi listed in the common venting tables must be reduced by cated or common venting system you must inspect the 10 the equivalent of one 90 elbow 0 90 x maximum venting system s general condition and look for signs common vent capacity of corrosion The existing vent pipe size must conform 18 The common vent diameter must always be at least as to these instructions and the provided venting tables If large as the largest vent connector diameter the existing vent
78. rmal operation Page 43 Troubleshooting Heating Sequence of Operation HEATING SEQUENCE OF OPERATION NORMAL AND ABNORMAL HEATING MODE POWER ON CONTROL SELF CHECK OKAY POLARITY OKAY YES IS THERE A PROPER GROUND YES A NORMAL OPERATION STATUS LED PULSE B THERMOSTAT CALLS FOR HEAT STATUS LED HEARTBEAT YES PRIMARY AND SECONDARY LIMIT SWITCHES CLOSED YES SECOND HIGH STAGE PRESSURE SWITCH CONTACTS OPEN TWO STAGE OR SINGLE STAGE THERMOSTAT CALL FOR HEAT A COMBUSTION AIR INDUCER ON LOW SPEED STATUS LED HEARTBEAT CONTINUED ON NEXT PAGE GAS VALVE OFF COMBUSTION AIR INDUCER OFF INDOOR BLOWER OFF RESET CONTROL BY TURNING MAIN POWER OFF POLARITY REVERSED STATUS ERROR CODE 5 4 SIGNAL HOLDS UNTIL UNIT IS PROPERLY GROUNDED STATUS ERROR CODE 5 3 COMBUSTION AIR INDUCER OFF INDOOR BLOWER ON HAS PRIMARY OR SECONDARY LIMIT RESET WITHIN MINUTES yes STATUS ERROR CODE 3 1 60 MINUTE LIMIT WATCHGUARD MODE GAS VALVE OFF COMBUSTION AIR INDUCER OFF INDOOR BLOWER OFF WITH DELAY STATUS ERROR CODE 4 5 GAS VALVE OFF COMBUSTION AIR INDUCER ON INDOOR BLOWER ON STATUS ERROR CODE 5 1 SEQUENCE HOLDS UNTIL ROLLOUT SWITCH IS RESET AND MAIN POWER IS INTERRUPTED OR T STAT IS CYCLED OFF ON FOR 3 SEC MINIMUM GAS VALVE OFF COMBUSTION AIR INDUCER OFF INDOOR BLOWER OFF CONTROL REMAINS UNTIL PRESSURE SWITCH IS DETECTED OPEN STATUS ERROR CODE 2 4 GAS VAL
79. rtment adjacent to the combustion air inducer The switch checks for proper combustion air inducer operation before allow ing ignition trial The switch is factory set and requires no adjustment Temperature Rise After the furnace has been started and supply and return air temperatures have been allowed to stabilize check the temperature rise If necessary adjust the blower speed to maintain the temperature rise within the range shown on the unit nameplate Increase the blower speed to decrease the temperature Decrease the blower speed to increase the temperature rise Failure to adjust the temperature rise may cause erratic limit operation Fan Control The fan on time of 30 seconds is not adjustable The heat fan off delay amount of time that the blower operates after the heat demand has been satisfied may be adjusted by changing DIP switches 3 and 4 See figure 35 and table 11 The unit is shipped with a factory fan off delay setting of 90 seconds The fan off delay affects comfort and is adjust able to satisfy individual applications Adjust the fan off delay to achieve a supply air temperature between 90 and 110 F at the moment that the blower is de energized Lon ger off delay settings provide lower return air temperatures shorter settings provide higher return air temperatures Thermostat Heat Anticipation Set the heat anticipator setting if adjustable according to the amp draw listed on the wiring diagram that is attach
80. t follow these instructions exactly a fire or explosion may result causing property damage personal injury or death Gas Valve Operation Figure 34 1 STOP Read the safety information at the beginning of this section 2 Set the thermostat to the lowest setting 3 Turn off all electrical power to the unit 4 This furnace is equipped with an ignition device which automatically lights the burners Do not try to light the burners by hand 5 Remove the upper access panel 6 Move switch on gas valve to OFF Do not force See figure 34 7 Wait five minutes to clear out any gas If you then smell gas STOP Immediately call your gas supplier from a neighbor s phone Follow the gas suppliers instruc tions If you do not smell gas go to next step HIGH FIRE ADJUSTMENT MANIFOLD SCREW PRESSURE POST under cap INLET PRESSURE POST GAS VALVE SHOWN IN ON IN ON POSITION FIGURE 34 8 Move switch on gas valve to ON Do not force See fig ure 34 9 Replace the upper access panel 10 Turn on all electrical power to to the unit 11 Set the thermostat to desired setting NOTE When unit is initially started steps 1 through 11 may need to be repeated to purge air from gas line 12 If the appliance will not operate follow the instructions Turning Off Gas to Unit and call your service techni cian or gas supplier Turning Off Gas to Unit 1 Set thermostat to the lowest setting 2 Turn off all electri
81. t pipe to the round collar of the flue transition If self drilling screws are used to attach the vent pipe it is recommended that three be used Drive one self drilling screw through the front and one through each side of the vent pipe and collar See figure 23 Install the first vent connector elbow at a minimum of six inches 152 mm from the furnace vent outlet See figure Venting Using a Masonry Chimney The following additional requirements apply when a lined masonry chimney is used to vent this furnace Masonry chimneys used to vent Category central fur naces must be either tile lined or lined with a listed metal lining system or dedicated gas vent Unlined masonry chimneys are prohibited See figures 24 and 25 for com mon venting A chimney with one or more sides exposed to the outside of the structure is considered to be an exterior chimney An exterior masonry chimney that is not tile lined must be lined with B1 vent or a listed insulated flexible metal vent An exterior tile lined chimney that is sealed and capped may be lined with a listed uninsulated flexible metal vent If the existing chimney will not accommodate a listed metal liner either the chimney must be rebuilt to accommodate one of these liners or an alternate approved venting meth od must be found Insulation for the flexible vent pipe must be an encapsu lated fiberglass sleeve recommended by the flexible vent pipe manufacturer See figure 24 AIMPORTANT
82. tective covering in front of the fur nace during cleaning 1 Turn off both electrical and gas power supplies to fur nace 6 2 Remove flue pipe and top cap some applications top cap can remain from the unit Label the wires from gas valve rollout switches prima ry limit switch and make up box then disconnect them 4 Remove the screws that secure the combustion air in 7 ducer pressure switch assembly to the collector box Carefully remove the combustion air inducer to avoid 8 damaging blower gasket If gasket is damaged it must be replaced to prevent leakage Remove the collector box located behind the combus tion air inducer Be careful with the collector box gas ket If the gasket is damaged it must be replaced to prevent leakage Disconnect gas supply piping Remove the screw se curing the burner box cover and remove cover Re move the four screws securing the burner manifold as sembly to the vestibule panel and remove the assembly from the unit Remove screws securing burner box and remove burner box NOX units only Remove screw securing NOX insert Remove NOX insert See figure 37 EL280UH BURNER COMBUSTION AIR INDUCER ASSEMBLY amp HEAT EXCHANGER REMOVAL Rollout Switches location Sensor Manifold And Gas Valve FIGURE 36 Page 40 00000000 00000000 Heat Exchanger Retention Rings Cross Over 9 Remove screws from both sides top and bottom of vestibule panel
83. terior or outside wall is PROHIBITED The chimney must first be lined with either type B1 vent or an insulated single wall flexible vent lining system which has been sized ac cording to the provided venting tables and the vent pipe manufacturer s instructions A fan assisted furnace may be commonly vented into an existing lined masonry chimney if the following conditions are met The chimney is currently serving at least one drafthood equipped appliance The vent connectors and chimney are sized according to the provided venting tables If type B1 double wall vent is used inside a chimney no oth er appliance can be vented into the chimney The outer wall of type B1 vent pipe must not be exposed to flue products A type B1 vent or masonry chimney liner shall terminate above the roof surface with a listed cap or a listed roof as sembly according to the terms of their respective listings and the vent manufacturer s instructions When inspection reveals that an existing chimney is not safe for the intended purpose it shall be rebuilt to conform to nationally recognized standards lined or relined with suitable materials or replaced with a gas vent or chimney suitable for venting EL280UH series units The chimney passageway must be checked periodically to ensure that it is clear and free of obstructions Do not install a manual damper barometric draft regulator or flue restrictor between the furnace and the chimney Neve
84. the unit operates properly and safely Use fiberglass sealing strips caulking or equiva lent sealing method between the plenum and the furnace cabinet to ensure a tight seal If a filter is installed size the return air duct to fit the filter frame Page 12 A 4 inch diameter flue transition is factory installed on the combustion air inducer outlet of all models Figure 16 shows the combustion air inducer as shipped from the factory Mounting Screws Location Mounting Screws FIGURE 15 UPFlow Position UPFLOW POSITION Top Vent Discharge Vent Pipe Flue ollector Box Transition gt C Pressure Jo Switch Make Up it SN p A N Box q Wo WN 2 q q AIR t FLOW FIGURE 16 AIMPORTANT The unit will not vent properly with the flue transition pointed down in the 6 o clock position The combustion air inducer may be rotated clock wise or counterclockwise by 90 to allow for top or side vent discharge in all applications When the unit is installed the flue transition must be in the 9 o clock 12 o clock or 3 o clock position If necessary reposition the combustion air inducer pres sure switch and or make up box as needed per the follow ing steps and see figures 17 through 22 1 Remove the four mounting screws which s
85. tom of the furnace and the platform to ensure that the furnace operates properly and safely The furnace is equipped with a removable bottom 20 X 25 X 1 panel to facilitate installation 508mm X 635mm X 25mm 7 Cleanable Filter Markings are provided on both sides of the furnace cabinet for installations that require side return air Cut the furnace cabinet at the maximum dimensions shown on page 2 NOTE 60C and 60D units that require air volumes over 1800 cfm 850 L s must have one of the following Return Air 1 Single side return air with transition to accommodate 20 Plenum x 25 x 1 in 508 x 635 x 25 mm cleanable air filter Re quired to maintain proper air velocity See figure 9 2 Single side return air with optional return airbase See fig ARN ure 10 3 Bottom return air Transition 4 Return air from both sides 5 Bottom and one side return air FIGURE 9 Refer to Engineering Handbook for additional information Optional Return Air Base Upflow Applications Only For use with A B C and D cabinets FURNACE lz FRONT IF BASE 193 Eey IS USED T Overall WITHOUT Maximum Minimum como ee emn e IAQ CABINET 1 279 m Meum 1 _ T RETURN AIR Unit side return air 356 ME PEERUM Opening Overall MUST AIR FLOW COVER BOTH Maximum UNIT AND T RETURN 5
86. upported separately NOTE When the furnace is installed on a platform in a crawlspace it must be elevated enough to avoid water damage and to allow the evaporator coil to drain Return Air Horizontal Applications Return air must be brought in through the end of a furnace installed in a horizontal application The furnace is equipped with a removable bottom panel to facilitate installation See figure 11 CAUTION If this unit is being installed in a space serviced by an exhaust fan power exhaust fan or other device which may create a negative pressure in the space take care when sizing the inlet air opening The in let air opening must be sized to accommodate the maximum voiume of exhausted air as as the maximum volume of combustion air required for all gas appliances serviced by this space Page 11 Horizontal Application Unit Installed on Platform Line contact is permissible but not preferred See the unit nameplate for clearances SEES See NES FIGURE 14 A WARNING Improper installation of the furnace can result in per sonal injury death Combustion and flue products must never be allowed to enter the return air system or the living space Use screws and joint tape to seal the return air system to the furnace In platform installations with bottom return air the furnace should be sealed airtight to the return air ple num A door must never be used as a portion of the return air

Lennox International Inc. EL280UH Furnace User Manual

Contents

Download Pdf Manuals

Related Search

Related Contents