Lennox G50UH-24A-045, Installation Instructions Manual

Page 1: ...27 Service 28 Repair Parts List 30 Ignition Control Board Diagnostic Codes 30 Troubleshooting 31 Start Up Performance Check List 35 WARNING Do not store or use gasoline or other flammable vapors and...

Page 2: ...ER KIT Either Side 23 3 4 603 I_1 25 635 TOP VIEW I I h r h h f _ A _ B _ 4 9 16 14 3 OPTIONAL EXTERNAL SIDE RETURN AIR FILTER KIT __ Either Side __ 40 1016 i AiR FLOW 1 5 8 16 1 Bottom Return Air Ope...

Page 3: ..._itor Combustion Air Orifice Combustion Air Pressure Switch Air Inducer Limit Shield Primary Limit NOx Insert NO x Units Only Secondary Limit Burner Bottom Shield Control Transformer _ _ _ X Blower As...

Page 4: ...el Gas Code or CSA B149 standards Vent installations must be consistent with the venting tables in this instruction and applicable provisions of local building codes This furnace is CSA Intemational c...

Page 5: ...be maintained during construction Air filters must be replaced upon construction comple tion The input rate and temperature rise must be set per the furnace rating plate One hundred percent 100 outdoo...

Page 6: ...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...

Page 7: ...ll have a minimum free area of 1 square inch 645 mm2 per 4 000 Btu 1 17 kW per hour of total input rating of all equipment in the en closure See figures 3 and 4 When communicating with the outdoors th...

Page 8: ...connections electrical supply vent connection and installation and service clearances 24 inches 610 mm at unit front The unit must be level NOTE 1 3 hp blower motors are equipped with four flex ible m...

Page 9: ...ition and filter Transition FIGURE 7 Optional Return Air Base Upflow Applications Only For use with B C and D cabinets only 20 X 25 X 1 508mm X635mm X 25mm Cleanable Filter _ Return Air Plenum J AIR F...

Page 10: ...Screw another nut onto the bolt on the inside of the fur nace base A flat washer may be added between the nut and the bottom of the unit 4 Adjust the outside nut to the appropriate height and tighten...

Page 11: ...e middle of the furnace to prevent sagging The straps must not interfere with the plenum or exhaust piping instaflation Securing screws should be 1 2 inch from the top edge and 1 1 2 inch from the sid...

Page 12: ...s 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...

Page 13: ...outlet 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 I central fur naces...

Page 14: ...vent or chimney suitable for venting G50UH X 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 barome...

Page 15: ...le wall connector piping shall be fastened by screws or other approved means 12 When the vent connector used for Category I ap pliances must be located in or pass through a crawl space or other areas...

Page 16: ...5 22 65 30 130 39 219 49 330 10 29 59 40 121 51 206 64 315 15 35 53 48 112 61 195 76 301 0 0 97 0 202 0 349 0 540 2 10 75 14 149 18 250 20 377 5 21 71 29 143 38 242 47 367 20 10 28 64 38 133 50 229 62...

Page 17: ...15 5 51 63 75 128 102 216 144 326 10 NR NR 95 116 128 201 182 308 15 NR NR NR NR 158 186 220 290 0 35 96 54 200 78 346 114 537 2 37 74 56 148 78 248 113 375 5 50 68 73 140 100 239 141 363 20 10 NR NR...

Page 18: ...89 47 142 64 220 15 2 22 53 35 96 49 153 66 235 3 24 55 36 102 51 163 68 248 1 21 54 33 99 46 157 62 246 20 2 22 57 34 105 48 167 64 259 3 23 60 35 110 50 176 66 271 1 20 62 31 113 45 181 60 288 30 2...

Page 19: ...nd 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 gener...

Page 20: ...nnection to the unit The tap must be accessible for test gauge connection See figure 19 NQ TE If emergency shutoff is necessarj4 shut off the main manual gas valve and disconnect main power to the fur...

Page 21: ...devices Right Side Piping Alternate ELECTROSTATIC DISCHARGE ESD Precautions and Procedures CAUTION CAUTION The furnace must be isolated from the gas supply system by closing its individual manual shu...

Page 22: ...rol board Any electronic air cleaner rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to any of the NEUTRAL terminals See figure 25 for control...

Page 23: ...OLTAGE _V ACC K43 EC _ IF USEO L I _ _ G S g S O COIlBIJ_IT ION AIR _IIIARYGAS PROVIi_ SWITCH LIMIT C _WBIJST I _NAIR _ INN ICERI_T_ ALEImNATE e V_lTE R X GERS HONEYWELL 6A5 VALVE 6AS VALVE orlo 000 F...

Page 24: ...WITH WIRE OF LIKE SIZE EA RATING INSULATION THICKNESS AND TERMINATION PIJS JI35_ _ IMPORTANT TO PREVENT MOTOR DURMDUT REVER CONNECT MORE SI P50 THAN ONE MOTOR LEAD TO ANY ONE CONNECTION ROOM THERMOSTA...

Page 25: ...on 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...

Page 26: ...tected after first ignition trial the igni tion control will repeat steps 3 and 4 four more times before locking out the gas valve WATCHGUARD flame failure mode The ignition control will then auto mat...

Page 27: ...eed to increase the temperature rise Failure to do adjust the temperature rise may cause erratic limit operation Fan Control Heating Mode The fan on delay of 45 seconds is not ad justable The fan offd...

Page 28: ...rated for high velocity air flow Table 1 lists recommended filter sizes Flue And Chimney Check the flue pipe chimney and all connections for tight ness and to make sure there is no blockage Electrica...

Page 29: ...ve debris knocked loose during cleaning 12 Attach the exhaust end positive pressure of the vacu um cleaner to the top of the heat exchanger section Any loose debris will be forced to the bottom of the...

Page 30: ...mostat FAST FLASH FAST FLASH SLOW FLASH ON Primary or secondary limit switch open Limit must close within 3 minutes or unit goes into 1 hour Watchguard Pressure switch open OR Blocked inlet exhaust ve...

Page 31: ...I RISES ABOVE 75 VOLTS I YESi in I1 I 1 GAS VALVE OFF COMBUSTION AIR INDUCER OFF _ _1 INDOOR BLOWER OFF WITH DELAY GAS VALVE I I LED 1 ON LED 2 SLOW FLASH I DE ENERGIZED I ISEQUENCE HOLDS UNTIL ROLLOU...

Page 32: ...COMBUSTION AIR INDUCER ON INDOOR BLOWER OFF I HAS CONTROL FA LED TO SENSE FLAME FOR NO FIVE CONSECUTIVE TRIES DURING A SINGLE I HEAT DEMAND t I_ IGNITION WATCHGUARD MODE GAS VALVE OFF I YES COMBUSTIO...

Page 33: ...HOLDS UNTIL VOLTAGE I HOLDS UNTIL UNIT IS I_1 PROPER GROUND I_IABOVE 75 VOLTS I_ RISES ABOVE 75 VOLTS PROPERLY GROUND I I NO I GAS VALVE OFF COMBUSTION AIR INDUCER OFF I ROLLOUT SWITCH MONITORED CONT...

Page 34: ...l t NO THERMOSTAT CALLS FOR COOLING _YES INDOOR BLOWER SWITCHES TO COOL SPEED THERMOSTAT OPENS 1 t YEs I AFTER NORMAL DELAY I THERMOSTAT OPENS COMBUSTION AIR INDUCER I AND HUM TERMINAL ARE DE ENERGIZ...

Page 35: ...Technician State Blower Motor H P Gas Piping Connections Tight Leak Tested LP Propane Gas D Line Pressure Regulator Pressure Flue Connections Tight Combustion Gas Tested Fan Control Setting 45 Second...