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31-5000729   Rev. 0   10-22   GEA

NF96DS 

96% Downflow Single Stage 

Constant Torque Motor Gas Furnace

Service 

Manual

READ  CAREFULLY.   

KEEP THESE INSTRUCTIONS

.

Summary of Contents for GE NF96DS

Page 1: ...31 5000729 Rev 0 10 22 GEA NF96DS 96 Downflow Single Stage Constant Torque Motor Gas Furnace Service Manual READ CAREFULLY KEEP THESE INSTRUCTIONS ...

Page 2: ...s 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 Electric shock hazard Can cause injury or death Before attempting to perform any service or maintenance turn the electrical power to unit OFF at disconnect switch es Unit may have multiple power supplies WARNING As with any mechanical equipment...

Page 3: ...00 96 0 4 Ton 1 2 120 60 1 15 8 4 40 144 NF96D090S4C 88 000 86 000 96 0 4 Ton 1 2 120 60 1 15 8 4 40 160 Note For vent length and clearances to combustibles please reference installation instructions MODEL NUMBER GUIDE MAJOR MINOR REVISION CABINET WIDTH B 17 5 C 21 NOMINAL CFM 3 1200 CFM 4 1600 CFM 5 2000 CFM DESIGN VARIANT S ECM 1 STAGE BRAND N GE PRODUCT F FURNACE GAS AFUE 96 96 EFFICIENCY APPLI...

Page 4: ...um Low Low cfm watts cfm watts cfm watts cfm watts cfm watts 0 00 1720 510 1545 355 1340 235 1240 190 1020 95 0 10 1700 530 1505 360 1310 245 1195 200 955 110 0 20 1675 545 1465 370 1275 255 1155 205 895 115 0 30 1640 555 1420 380 1230 270 1120 215 835 125 0 40 1600 565 1380 395 1180 280 1060 225 785 135 0 50 1560 570 1340 400 1140 290 1015 235 715 145 0 60 1500 565 1300 420 1095 305 965 245 640 1...

Page 5: ...rmination 90 Furnaces Only US Only 51W11 2 3 Vent Version Concentric Vent Kit 90 Furnaces Only US Only 71M80 1 1 2 Vent Version 69M29 2 Vent Version 60L46 3 Vent Version Concentric Vent Kit 90 Furnaces Only Canada Only 44W92 1 1 2 and 2 Vent Version 44W93 3 Vent Version Twinning Kit 16W72 Constant Torque Gas Furnace Twinning Kit Note For vent length and clearances to combustibles please reference ...

Page 6: ... transformer and door switch BAG ASSEMBLY BLOWER MOTOR hidden COMBUSTION AIR INDUCER BURNER BOX ASSEMBLY includes flame sensor rollout switches and ignitor GAS VALVE BLOWER DECK HEAT EXCHANGER COLD END HEADER BOX PRIMARY LIMIT BLOWER ACCESS PANEL HEATING ACCESS PANEL COMPARTMENT COMPARTMENT ...

Page 7: ...o the transformer T1 The breaker is rated at 3A at 32V If the current exceeds this limit the breaker will trip and all unit operation will shutdown The breaker can be manually reset by pressing the button on the face Integrated Ignition Control A92 Shock hazard Disconnect power before servicing Control is not field repairable If control is inoperable simply replace entire control Can cause injury ...

Page 8: ...heat demand 4 Low Flame Signal check flame sensor 5 Watchguard burner failed to light exceeded maximum number of retries or recycles 6 Not Used 7 Primary or Secondary Limit Open or Watchguard Mode Limit Switch Open longer than 3 minutes 8 Rollout Switch Open 9 Pressure Switch failed to close or opened during heat demand 10 Watchguard Pressure Switch opened 5 times during one heat demand 11 Pressur...

Page 9: ...s been satisfied can be adjusted by moving the jumper to a different setting The unit is shipped with a factory fan off setting of 90 seconds For customized comfort monitor the supply air temperature once the heat demand is satisfied Note the supply air temperature at the instant the blower is de energized Adjust the fan off delay to achieve a supply air temperature between 90 110 at the instant t...

Page 10: ...ean without removing any part of the burners During operation flame is sensed by current passed through the flame and sensing electrode The ignition control allows the gas valve to remain open as long as flame signal is sensed NOTE The NF96DS is polarity sensitive Make sure that the furnace is wired correctly and is properly grounded A microamp DC meter is needed to check the flame signal on the i...

Page 11: ...y shut off If the gas valve must be replaced the same type valve must be used 24VAC terminals and gas control switch are located on top of the valve All terminals on the gas valve are connected to wires from the ignition control 24V applied to the terminals opens the valve Inlet and outlet pressure taps are located on the valve A manifold adjustment screw is also located on the valve An LP Propane...

Page 12: ...Dial to DC MicroAmps Multi Meter To Control Sensor T erminal T o Flame Terminal Remove Sensor Wire from Intergrated Control and Connect Alligator Clip to Terminal on Control Flame Sensor Terminal Flame Sensor Wire Remove Sensor Wire from Intergrated Control and Connect Alligator Clip to Frame Sensor Lead Intergrated Control ...

Page 13: ...eck ignitor for correct voltage Insert meter probes into terminals 2 and 4 use small diameter probes in order not to damage plug Check voltage during 20 second ignitor warm up period Voltage should read 120 volts 10 If voltage reads below these values check for correct supply voltage to furnace Integrated Control Detail Test 1 Check ignitor circuit for correct resistance Remove 4 pin plug from con...

Page 14: ...ice to insure proper flow through the heat exchanger The switch is a SPST N O pressure switch electrically connected to the integrated control The purpose of the switch is to prevent burner operation if the combustion air inducer is not moving enough air for proper combustion Figure 10 Pressure Switch On start up the switch monitors whether the combustion air inducer is operating It closes a circu...

Page 15: ...nd with hose from the positive side of the manometer to the tee in the positive line NOTE tive However the port reads less negative pressure than the port 4 Operate unit and observe manometer reading Readings will change as heat exchanger warms a Take one reading immediately after start up b Take a second reading after unit has reached steady state approximately 5 minutes This will be the pressure...

Page 16: ...ough Table 11B Wrong pressure switch installed in the unit or pressure switch is out of calibration Check that the correct pressure switch is installed in the unit Replace pressure switch if necessary Miswiring of furnace or improper connections at pressure switch Check for correct wiring and loose connections Correct wiring and or replace any loose connections Pressure switch failure If all the a...

Page 17: ...nt in tests 1 and 2 and motor is not operating properly replace motor The motor is not field repairable If replacing the indoor blower motor or blower wheel is necessary placement is critical The blower wheel must be centered in the blower housing as shown in Figure 13 When replacing the indoor blower motor the set screw must be aligned and tightened with the motor shaft as shown in Figure 14 Seco...

Page 18: ... If 24 volts is not present problem may be up stream of plug P49 Proceed to test 4 Multi Meter set to VAC 12 0 12 0 24 Multi Meter set to VAC problem is with the harness If voltage is not present problem may be may be with the integrated control Check for 120 volts across terminals CIRC and Neutrals on the integrated control If voltage is present problem is with the harness If voltage is not prese...

Page 19: ...of the three motor connector pins These should all read approximately the same resistance within an ohm 3 Check to see if the blower wheel spins freely Figure 17 Motor Test Scale Measurement Range in Words ohms 2 M two megohms two million ohms 0 2 000 000 200 K two hundred kil ohms two hundred thousand ohms 0 200 000 20 K twenty kilo ohms twenty thousand ohms 0 20 000 2 K two kilo ohms two thousan...

Page 20: ... Low temperature solvent cement is recommended during cooler weather Metal or plastic strapping may be used for vent pipe hangers Uniformly apply a liberal coat of PVC primer for PVC or use a clean dry cloth for ABS to clean inside socket surface of fitting and male end of pipe to depth of fitting socket NOTE Canadian Applications Only Pipe fittings primer and solvent cement used to vent exhaust t...

Page 21: ...fully inserted to distribute cement evenly DO NOT turn ABS or cellular core pipe NOTE Assembly should be completed within 20 seconds after last application of cement Hammer blows should not be used when inserting pipe Capacity Vent Pipe Dia in Standard Concentric Flush Mount Kit Field Fabricated 1 1 2 inch 2 inch 3 inch 51W11 71M80 US 4 44W92 CA 69M29 US 4 44W92 CA 60L46 US 4 44W93 CA 045 1 1 1 2 ...

Page 22: ...collection trap and lines Figure 20 CHIMNEY OR GAS VENT Check sizing for water heater only FURNACE Replaced by EL195 WATER HEATER OPENINGS To Adjacent Room If the furnace replaces a furnace which was commonly vented with another gas appliance appliance must be checked Without the heat of the original furnace flue products the existing vent pipe is probably oversized for the single water heater or ...

Page 23: ...andard roof and wall terminations described in section Exhaust Piping Terminations should be used Exhaust vent termination pipe is sized to optimize the velocity of the exhaust gas as it exits the termination Refer to Table 13 In some applications which permit the use of several different sizes of vent pipe a combination vent pipe may be used Contact GE Appliances Technical Services Department for...

Page 24: ... Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation Table 10A Maximum Allowable Intake or Exhaust Vent Length in Feet Standard Termination at Elevation 2 001 10 000 ft Number of 90 Elbows Used 2 Pipe 2 1 2 Pipe 3 Pipe Capacity Capacity Capacity 045 070 090 045 070 090 045 070 090 1 35 25 15 100 73 43 127 127 1...

Page 25: ...vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation Table 10C Maximum Allowable Intake or Exhaust Vent Length in Feet Concentric Termination at Elevation 2 001 10 000 ft Number of 90 Elbows Used 2 Pipe 2 1 2 Pipe 3 Pipe Capacity Capacity Capacity 045 070 090 030 045 070 090 030 045 070 090 1 35 25 15 90 63 39 111 111 104 ...

Page 26: ...be included in the total vent length calculation NOTE Contact your local FTC if more than 85ft of venting is needed Table 11A Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or Basement Using Ventilated Attic or Crawl Space For Intake Air in Feet Standard Termination at Elevation 2 001 10 000 ft Number of 90 Elbows Used 1 1 2 Pipe 2 Pipe 2 1 2 Pipe 3 Pipe Capacity Capacit...

Page 27: ...horizontal runs of exhaust pipe When transitioning up in pipe size use the shortest length of 2 PVC pipe possible NOTE Exhaust pipe and intake pipe must be the same diameter Figure 23 Typical Intake Pipe Connections Direct Vent Applications 2 Pipe size determined in table 7 2 2 2 2 or TOP VIEW EXHAUST INTAKE TRANSITION 3 2 2 TRANSITION 3 2 2 1 1 2 or TRANSITION NOTE 1 1 2 Vent Pipe Diameter Allowe...

Page 28: ...with the protective screen should always be directed forward or sideways 2 If intake air is drawn from a ventilated attic Figure 25 or ventilated crawlspace Figure 26 the exhaust vent length must not exceed those listed in Table 11A through Table 11B If 3 diameter pipe is used reduce to 2 diameter pipe at the termination point to accommodate the debris screen 3 Use a sheet metal screw to secure th...

Page 29: ... for details Position termination according to location given in Figure 28 or Figure 37 In addition position termination so it is free from any obstructions and 12 above the average snow accumulation At vent termination care must be taken to maintain protective coatings over building materials prolonged exposure to exhaust condensate can destroy protective coatings It is recommended that the exhau...

Page 30: ...ded in the current edition of the ASHRAE Fundamentals Handbook 2 Poly Propylene vent pipe PP by Duravent and Centrotherm 3 Vent length in table is equivalent length Each elbow is equivalent to 5ft of straight pipe and should be included when measuring total length NOTE Concentric terminations are the equivalent of 5 and should be considered when measuring pipe length NOTE Maximum uninsulated vent ...

Page 31: ...hes 152mm for appliances 10 000 pliances 10 000 Btuh 3kw and 50 000 pliances 50 000 Btuh 15kw 6 inches 152mm for appliances 10 000 Btuh 3kw 12 inches 305mm for appliances 10 000 Btuh 3kw and 100 000 Btuh 30kw 36 inches 9m for appliances 100 000 Btuh 30kw 3 feet 9m above if within 10 feet 3m horizontally 6 feet 1 8m 7 feet 2 1m 12 inches 305mm 1 In accordance with the current ANSI Z223 1 NFPA 54 Na...

Page 32: ...iping should terminate straight down using two 90 elbows see Figure 29 4 Exhaust piping must terminate straight out or up as shown A reducer may be required on the exhaust piping at the point where it exits the structure to improve the velocity of exhaust away from the intake piping See Table 13 Capacity Exhaust Pipe Size Termination Pipe Size 045 070 2 51mm 21 2 64mm 3 76mm 1 1 2 38mm 90 2 51mm 0...

Page 33: ...L STRAP Clamp and sheet metal strap must be field installed to support the weight of the termination kit FLASHING Not Furnished CLAMP FIELD PROVIDED REDUCER MAY BE REQUIRED TO ADAPT DIFFERENT VENT PIPE SIZE TO TERMINATION 1 1 2 38mm accelerator provided on 71M80 44W92 kits for 045 and 070 models 12 305mm INTAKE AIR EXHAUST VENT Figure 35 Direct Vent Concentric Wall Termination 71M80 69M29 or 60L46...

Page 34: ...learance under veranda porch deck or balcony 12 Equal to or greater than soffit depth 3 feet 9m 12 3 feet 9m within a height 15 feet 4 5m above the meter regulator assembly 3 feet 9m 6 inches 152mm for appliances 10 000 Btuh 3kw 12 inches 305mm for appliances 10 000 Btuh 3kw and 100 000 Btuh 30kw 36 inches 9m for appliances 100 000 Btuh 30kw 3 feet 9m above if within 10 feet 3m horizontally 6 feet...

Page 35: ...3 If exhaust piping must be run up a side wall to position above snow accumulation or other obstructions piping must be supported every 24 inches 610mm When exhaust piping must be run up an outside wall any reduction in exhaust pipe size must be done after the final elbow 4 Distance between exhaust pipe terminations on multiple furnaces must meet local codes Figure 39 Non Direct Vent Application U...

Page 36: ...above grade or average snow accumulation B Horizontal separation between intake and exhaust C Minimum from end of exhaust to inlet of intake D Exhaust pipe length E Wall support distance from top of each pipe intake exhaust 12 305 mm Min 12 305 mm Min 6 152 mm Min 24 610 mm Max 9 227 mm Min 12 305 mm Min 16 405 mm Max 6 152 mm Max 6 152 mm Min 24 610 mm Max 9 227 mm Min 12 305 mm Min 20 508 mm Max...

Page 37: ... for all provinces of Canada GEA approves the following termination for use in all provinces of Canada C 12 D B A 2 51MM Vent Pipe 3 76MM Vent Pipe 12 305 mm Min 12 305 mm Min 6 152 mm Min 24 610 mm Max 6 152 mm Max 6 152 mm Min 24 610 mm Max 6 152 mm Max A Clearance above grade or average snow accumulation B Horizontal separation between intake and exhaust C Exhaust pipe length D Wall support dis...

Page 38: ...ee Figure 47 or Figure 48 4 Install drain trap using appropriate PVC fittings glue all joints Glue the provided drain trap as shown in Figure 47 or Figure 48 Route the condensate line to an open drain Condensate line must maintain a 1 4 downward slope from the furnace to the drain 5 Figure 44 shows the furnace and evaporator coil using a separate drain If necessary the condensate line from the fur...

Page 39: ...ensate drain Condensate Drain Connection Evaporator Drain Line vent required FurnaceCondensate DrainConnection From Evaporator Coil Optional Field Provided Vent 1 min 2 max above condensate drain Figure 45 Condensate Trap with Optional Overflow Switch When combining the furnace and evaporator coil drains together the A C condensate drain outlet must be vented to relieve pressure in order for the f...

Page 40: ...ch PVC Pipe Not Furnished Drain Assembly for 3 4 inch Drain Pipe Condensate Drain Connection In Unit Condensate Drain Connection In Unit Vent To Drain Condensate Drain Connection In Unit Optional Condensate Drain Connection OptionalDrainPipingFromTrap DrainTrapAssembly Furnished DrainTrap Assembly with 1 2 inch Piping DrainTrap Assembly with 3 4 inch Piping 1 2 inch 3 4 inch 1 25 mm Min 2 50 mm Ma...

Page 41: ...2 inch PVC To Drain 90 Elbow 1 2 inch PVC Not Furnished 1 2 inch PVC Pipe Not Furnished Drain Assembly for 3 4 inch Drain Pipe 90 Street Elbow 1 2 inch PVC Not Furnished Condensate Drain Connection In Unit Adapter 1 2 inch slip X 1 2 inch mpt Not Furnished Condensate Drain Connection In Unit Vent To Drain Condensate Drain Connection In Unit Drain Trap Assembly with 3 4 inch Piping Vent To Drain Fu...

Page 42: ...ting demand 5 Wait for the combustion air inducer to stop Set the thermostat to initiate a heating demand and again allow the burners to fire for approximately 3 minutes 6 Adjust the thermostat to deactivate the heating demand and again wait for the combustion air inducer to stop At this point the trap should be primed with sufficient water to ensure proper condensate drain operation If you do not...

Page 43: ...esistant to action of liquefied petroleum gases Testing Gas Piping In case emergency shutdown is required turn off the main shut off valve and disconnect the main power to unit These controls should be properly labeled by the installer IMPORTANT When pressure testing gas lines the gas valve must be disconnected and isolated Gas valves can be damaged if subjected to more than 0 5 psig 14 W C See Fi...

Page 44: ...er as soon as an accurate reading has been obtained Take care to remove barbed fitting and replace threaded plug 6 Start unit and perform leak check Seal leaks if found Capacity Gas Manifold Pressure in w g Supply Line Pressure in w g 0 10 000 ft 0 4500 ft 4501 5500 ft 5501 6500 ft 6501 7500 ft 7501 10000 ft All Sizes Natural 3 5 3 3 3 2 3 1 3 5 4 5 13 0 LP Propane 10 0 9 4 9 1 8 9 10 0 11 0 13 0 ...

Page 45: ...7501 10 000 feet require an orifice change Units installed at altitudes of 4501 10 000 feet 1373 to 3048 m require a pressure switch change which can be ordered separately Table 17 and Table 18 list conversion kit and pressure switch requirements at varying altitudes The combustion air pressure switch is factory set and requires no adjustment Capacity 0 7 500 ft 0 2 286 m 7 501 10 000 ft 2 286 304...

Page 46: ...the voltage between Line Neutral and C as a function of load indicates a poor or partial ground Compare the readings to Table 19 If the readings exceed the maximum shown in Table 19 make repairs before operating the furnace 2 In addition measure the AC voltage from Line Hot to Line Neutral spade terminals on the integrated control See Figure 52 This voltage should be in the range of 97 to 132 VAC ...

Page 47: ...y and return air plenums Insert manometer hose flush with inside edge of hole or insulation Seal around the hose with permagum Connect the zero end of the manometer to the discharge supply side of the system On ducted systems connect the other end of manometer to the return duct as above 3 With only the blower motor running and the evaporator coil dry observe the manometer reading Adjust blower mo...

Page 48: ...ic pressure drop than standard efficiency glass foam filters If the pressure drop is too great system capacity and performance may be reduced The pressure drop may also cause the limit to trip more frequently during the winter and the indoor coil to freeze in the summer resulting in an increase in the number of service calls Before using any filter with this system check the specifications provide...

Page 49: ...lector box 11 Mark and remove wires from pressure switch assembly Remove pressure switch assembly Keep tubing attached to pressure switch assembly 12 Disconnect the plug from the combustion air inducer Remove two screws which secure combustion air inducer to collector box Remove combustion air inducer assembly Remove ground wire from vest panel 13 Remove electrical junction box from the side of th...

Page 50: ...eak test has been completed Do not use matches candles flame or other sources of ignition to check for gas leaks CAUTION Cleaning the Burner Assembly if needed 1 Turn off electrical and gas power supplies to furnace Remove upper and lower furnace access panels 2 Disconnect the 2 pin plug from the gas valve 3 Remove the burner box cover if equipped 4 Disconnect the gas supply line from the gas valv...

Page 51: ...Page 51 31 5000729 Rev 0 Wiring Diagram 045 3B 070 4B 090 4C ...

Page 52: ...IMPROPER GROUND LED FLASHES CODE 13 LOW LINE VOLTAGE CONTROL WILL NOT RESPOND TO A CALL FOR HEATING UNTIL VOLTAGE RISES ABOVE 75 VOLTS LED FLASHES CODE 8 ROLLOUT SWITCH OPEN GAS VALVE OFF COMBUSTION AIR INDUCER ON INDOOR BLOWER ON SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES AND POWER IS RESET OR T STAT IS INTERRUPTED FOR MINIMUM OF 1 SECOND LED FLASHES CODE 12 FLAME SENSED WITHOUT GAS VALVE ENERGIZ...

Page 53: ...AME SIGNAL 1 5 MICROAMPS OR GREATER FLAME PRESENT 15 SECONDCOMBUSTIONAIRINDUCERPREPURGE INITIATEDBYCLOSEDPRESSURESWITCH IGNITOR WARM UP 20 SECONDS 4 SECOND TRIAL FOR IGNITION GAS VALVE OPENS IGNITOR ENERGIZED FOR FIRST 3 SECONDS OF THE TRIAL FLAME STABILIZATION PERIOD FLAME RECTIFICATION CURRENT CHECK CAN FLAME BE PROVEN WITHIN 4 SECONDS AFTER GAS VALVE OPENS 0 5 microamps LED FLASHES CODE 13 LOW ...

Page 54: ... FLASHES CODE 13 LOW VOLTAGE CONTROL WILL CONTINUE TO CALL FOR COOLING IN THIS CONDITION LED FLASHES CODE 8 ROLLOUT SWITCH OPEN GAS VALVE OFF COMBUSTION AIR INDUCER ON INDOOR BLOWER ON SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES AND MAIN POWER IS INTERRUPTED OR THERMOSTAT IS CYCLED OFF ON FOR 1 SEC MIN LED FLASHES STEADY CIRCUIT BOARD FAILURE GAS VALVE OFF COMBUSTION AIR INDUCER OFF INDOOR BLOWER O...

Page 55: ...SPEED EAC TERM REMAINS ON THERMOSTAT OPENS THERMOSTAT OPENS MANUAL FAN SELECTION MADE AT THERMOSTAT CONTROL G ENERGIZES SYSTEM FAN AT FAN SPEED EAC TERM ENERGIZED SYSTEM FAN SWITCHES TO HEAT SPEAD AFTER 30 SECOND DELAY EAC AND HUM TERMINALS REMAIN ON SYSTEM FAN CONTINUES FAN SPEED WITHOUT INTERRUPTION EAC TERMINAL REMAIN ON HUM TERMINALS ARE ENERGIZED WITH COMBUSTION AIR BLOWER HUM TERMINALS OFF A...

Page 56: ...Page 56 31 5000729 Rev 0 Printed in the U S A All specifications and illustrations subject to change without notice and without incurring obligations ...

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