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Allied A97DF2E Service Manual

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SERVICE MANUAL
A97DF2E & 97G2DFE
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.
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer (or
equivalent), service agency or the gas supplier.
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.
508434-01
WARNING
WARNING

Table of Contents

Technical Specifications - A97DF2E ............................2
Technical Specifications - 97G2DFE ...........................7
Parts Arrangement.....................................................12
Electrical ....................................................................13
Placement & Installation ............................................27
Joint Cementing Procedure .......................................28
Venting Practices .......................................................29
Vent Piping Guidelines ..............................................30
Condensate Piping ....................................................45
Start-Up .....................................................................49
Heating System Service Checks ...............................50
Typical Operating Characteristics ..............................54
Maintenance ..............................................................55
Wiring Diagram ..........................................................58
Electronic Ignition ......................................................59
Field Wiring Applications ...........................................61
(Continued) ................................................................66
(Continued) ................................................................67
Sequence of Operation..............................................69
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment and wear gloves
and protective clothing.
*P508434-01*
Issue 2350
CAUTION
(P) 508434-01
Page 1 of 69

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Summary of Contents for Allied A97DF2E

  • Page 1: Table Of Contents

    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. Table of Contents Technical Specifications - A97DF2E ......2 Technical Specifications - 97G2DFE ......7 Parts Arrangement.............12 Electrical ..............13...

  • Page 2: Technical Specifications - A97Df2E

    Technical Specifications - A97DF2E MODEL NUMBER GUIDE A 9 7 D F 2 E 1 1 0 C 2 0 S - 0 1 Major Revision Code Flagship Numeric Code AFUE Heat Exch 97 = 97% Efficency S = Stainless Steel Heat...
  • Page 3 BLOWER DATA: DOWNFLOW A97DF2E045B12S PERFORMANCE (Less Filter) Rise Range °F Air Volume / Watts at Various Blower Speeds External Static High Medium-High Medium Medium-Low Pressure Stage Stage Watts Watts Watts Watts Watts in. w.c. 0.10 1434 1275 1169 0.20 1401 1237 1140 0.30...
  • Page 4 BLOWER DATA: DOWNFLOW A97DF2E110C20S PERFORMANCE (Less Filter) Rise Range °F Air Volume / Watts at Various Blower Speeds External Static High Medium-High Medium Medium-Low Pressure Stage Stage Watts Watts Watts Watts Watts in. w.c. 0.10 2174 1920 1754 1631 1441 0.20 2136 1877...
  • Page 5 ACCESSORY LIST Description Catalog Number Return Air Base Return Air Base 17.5 Inch 68W62 Return Air Base 21.0 Inch 68W63 Return Air Base 24.5 Inch 68W64 Downflow Combustible Flooring Base 17.5" B Width 11M60 21.0" C Width 11M61 External Filter Rack kits 1 pack (16 x 25) 1.841018 10 pack (16 x 25)
  • Page 6 ACCESSORY LIST Description Catalog Number High Altitude Pressure Swiches 2-Stage 97% UH/DF (4,501 - 7,500 ft) [045] 14A51 2-Stage 97% UH/DF (4,501 - 7,500 ft) [070] 14A48 2-Stage 97% UH/DF (4,501 - 7,500 ft) [090] 14A54 2-Stage 97% UH/DF (4,501 - 7,500 ft) [110] 25B93 2-Stage 97% UH/DF (7,501 - 10,000 ft) [045] 14A53...

  • Page 7: Technical Specifications - 97G2Dfe

    Technical Specifications - 97G2DFE MODEL NUMBER GUIDE 9 7 G 2 U H 0 7 0 B E 1 2 - 0 1 AFUE MAJOR REVISION 97% EFFICIENCY NUMERIC CODE 12 = 3 TON ADD ON COOLING 16 = 4 TON ADD ON COOLING STAGES 20 = 5 TON ADD ON COOLING 2 = TWO STAGE...
  • Page 8 BLOWER DATA: DOWNFLOW 97G2DF045BE12 PERFORMANCE (Less Filter) Rise Range °F Air Volume / Watts at Various Blower Speeds External Static High Medium-High Medium Medium-Low Pressure Stage Stage Watts Watts Watts Watts Watts in. w.c. 0.10 1434 1275 1169 0.20 1401 1237 1140 0.30...
  • Page 9 BLOWER DATA: DOWNFLOW 97G2DF110CE20 PERFORMANCE (Less Filter) Rise Range °F Air Volume / Watts at Various Blower Speeds External Static High Medium-High Medium Medium-Low Pressure Stage Stage Watts Watts Watts Watts Watts in. w.c. 0.10 2174 1920 1754 1631 1441 0.20 2136 1877...
  • Page 10 ACCESSORY LIST Description Catalog Number Return Air Base Return Air Base 17.5 Inch 68W62 Return Air Base 21.0 Inch 68W63 Return Air Base 24.5 Inch 68W64 Downflow Combustible Flooring Base 17.5" B Width 11M60 21.0" C Width 11M61 External Filter Rack kits 1 pack (16 x 25) 1.841018 10 pack (16 x 25)
  • Page 11 ACCESSORY LIST Description Catalog Number High Altitude Pressure Swiches 2-Stage 97% UH (4,501 - 7,500 ft) [030] 14A47 2-Stage 97% UH/DF (4,501 - 7,500 ft) [045] 14A51 2-Stage 97% UH/DF (4,501 - 7,500 ft) [070] 14A48 2-Stage 97% UH/DF (4,501 - 7,500 ft) [090] 14A54 2-Stage 97% UH/DF (4,501 - 7,500 ft) [110] 25B93...

  • Page 12: Parts Arrangement

    Parts Arrangement CONTROL BOX (Includes integrated control, transformer and door switch) CONSTANT TORQUE BLOWER MOTOR (hidden) BAG ASSEMBLY (shipping location) COMBUSTION AIR INDUCER BLOWER DECK HEAT EXCHANGER ASSEMBLY OUTER ACCESS PANEL COLD END HEADER BOX COMBUSTION AIR INDUCER PRESSURE SWITCH PRIMARY LIMIT BURNER BOX ASSEMBLY (includes sensor, rollout switches and ignitor)

  • Page 13: Electrical

    PRESS TO RESET handling the control. A97DF2E / 97G2DFE unit components are shown in Figure Figure 3. Circuit Breaker (CB8) 1. The gas valve, combustion air inducer and burners can be accessed by removing the access panel. Electrical...
  • Page 14 times with an inter purge and warm-up time between trials Pin # Function of 35 seconds. After a total of five trials for ignition (including Gas Valve Second Stage the initial trial), the control goes into Watchguard-Flame Second Stage Pressure Switch Failure mode.
  • Page 15 24VAC Indoor Ignitor and Combustion Blower Terminals Air Inducer Neutrals Flame Sense S4 DIP Switches Diagnostic Push Button On Board Links 3/16” QUICK CONNECT TERMINALS THERMOSTAT CONNECTIONS (TB1) FLAME SENSE SIGNAL DS = DEHUMIDIFICATION SIGNAL HI COOL 24VAC W2 = HEAT DEMAND FROM 2ND STAGE TSTAT LO COOL 24VAC W1 = HEAT DEMAND FROM 1ST STAGE TSTAT LO HEAT 24VAC...
  • Page 16 2ND STAGE HEAT ON DELAY 7 MIN UPSTAGE THERMOSTAT SELECTION DELAY COOLING BLOWER-OFF DELAY TWO STAGE THERMOSTAT 12 MIN UPSTAGE *45 SECOND DELAY COOL BLOWER 1−STAGE OFF DELAY THERMOSTAT (TIMED STAGING) −SEE SW #2 HSI/CAI 2 SECOND COOL BLOWER HEATING BLOWER−OFF DELAY OFF DELAY 90 SECOND HTG BLOWER...
  • Page 17 Display Action (when button released) No change (idle)* Remain in idle mode Solid “E” Enter diagnostic recal mode Solid “F” Enter flame signal mode * No change implies the display will continue to show whatever is currently being displayed for normal operation (blinking decimal, active error code, heat state, etc.) Table 3.
  • Page 18 Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover E223 Low pressure switch failed open. Check pressure (inches w.c.) of low pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared E224 Low pressure switch failed closed.
  • Page 19 Integrated Control DIP Switches between 90° and 110°F at the exact moment that the blower A97DF2E / 97G2DFE units are equipped with a two- is de-energized. Longer off delay settings provide lower stage integrated control. This control manages ignition supply air temperatures;...
  • Page 20 Switch 5 (seconds) 45 (Factory) A97DF2E / 97G2DFE units are equipped with a constant torque ECM motor. It has a DC motor coupled to an Table 6. Blower Off Cooling Mode Delay Switch electronic control module both contained in the same motor Settings housing.
  • Page 21 Scale Measurement Range in Words ohms ALIGN AND TIGHTEN SET SCREW WITH two megohms - two million ohms 0 - 2,000,000 FLAT SIDE OF MOTOR SHAFT two hundred kil-ohms - 200 K 0 - 200,000 two hundred thousand ohms twenty kilo-ohms - 20 K 0 - 20,000 twenty thousand ohms...
  • Page 22 Multi−Meter (set to VAC) Multi−Meter (set to VAC) Test 1 Test 3 (if necessary) Turn on power to unit. Check for 120 volts across terminals Check for 120 volts across terminals “L1” and “Neutrals” on “L” and “N” on input plug P48. If voltage is present continue the integrated control.
  • Page 23 Inlet and outlet pressure taps are located on the valve. A Figure 11. Primary Limit Control (S10) regulator adjustment screw is located on the valve. LPG change over kits are available from Allied. Kits include burner orifices and a gas valve. Flame Rollout Switches (S47) Flame rollout switch is a high temperature limit located on top of the burner box, one on each side.- See Figure 12.
  • Page 24 Burner Assembly Ignitor Intake Air Top Cap Sensor Rollout Switches Two-Stage Gas Valve Manifold And Gas Orifices Burner Box Cover Figure 12. Heating Components Page 24 of 69 Issue 2350 508434-01...
  • Page 25 Test 1 Check ignitor circuit for correct resistance. Remove 5−pin plug from control. Check ohms reading across terminals 1 and 5. If value is correct, this is the only test needed. If the reading on the meter is not correct, (0 or infinity) then a second test is needed.
  • Page 26 Combustion Air Inducer Pressure Switch (S18) (Figure A97DF2E / 97G2DFE series units are equipped with a dual combustion air pressure switch (first and second stage) located on the CEHB. The switch is connected to the cold end header box by means of flexible silicone hoses.

  • Page 27: Placement & Installation

    SPECIFICATION PVC & CPVC Primer F656 IMPORTANT PVC Solvent Cement D2564 A97DF2E / 97G2DFE exhaust and intake connections CPVC Solvent Cement F493 are made of PVC. Use PVC primer and solvent cement ABS Solvent Cement D2235 when using PVC vent pipe. When using ABS vent pipe,...

  • Page 28: Joint Cementing Procedure

    STANDARD CONCENTRIC Outdoor Outdoor Exhaust 1-1/2” 2” 3” Exhaust Flush VENT Accelerator Concentric Concentric Concentric Accelerator Mount Kit Model PIPE DIA. (Dia. X Length) (in.) (Dia. X Length) 71M80 or 69M29 or 60L46 or 1-1/2” X 12” 2” X 12” 51W11** +44W92++ +44W92++...

  • Page 29: Venting Practices

    Immediately after applying last coat of cement to pipe, appliances, the venting system is likely to be too large to and while both inside socket surface and end of pipe properly vent the remaining attached appliances. are wet with cement, forcefully insert end of pipe into Conduct the following test while each appliance is operating socket until it bottoms out.

  • Page 30: Vent Piping Guidelines

    If the furnace replaces a furnace which was commonly vented with another gas appliance, The A97DF2E / 97G2DFE can be installed as either a the size of the existing vent pip for that gas appliance must be checked. Without the heat of the Non-Direct Vent or a Direct Vent gas central furnace.
  • Page 31 Use the following steps to correctly size vent pipe diameter. Capacity Min. Vent Length* 15 ft or 5 ft plus 2 elbows or 045, 070, 090, 110 10 ft plus 1 elbow 030, 045, *Any approved termination may be added to the minimum Furnace capacity? 070, 090, length listed.
  • Page 32 Maximum Allowable Intake or Exhaust Vent Length (feet) Standard Termination at Elevation 0 - 4,500 ft 1-1/2” Pipe 2” Pipe 2-1/2” Pipe 3” Pipe Number of 90° Model Model Model Model Elbows Used Standard Termination at Elevation 4,501 - 10,000 ft 1-1/2”...
  • Page 33 Maximum Allowable Intake or Exhaust Vent Length (feet) Concentric Termination at Elevation 0 - 4,500 ft 1-1/2” Pipe 2” Pipe 2-1/2” Pipe 3” Pipe Number of 90° Model Model Model Model Elbows Used Concentric Termination at Elevation 4,501 - 10,000 ft 1-1/2”...
  • Page 34 Maximum Allowable Exhaust Vent Lengths Using Ventilated Attic or Crawl Space for Intake Air in Feet Standard Termination at Elevation 0 - 10,000 ft 1-1/2” Pipe 2” Pipe 2-1/2” Pipe 3” Pipe Number of 90° Model Model Model Model Elbows Used NOTE: Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation.
  • Page 35 Pipe size determined in Table 13A NOTE: 1-1/2” Vent Pipe Diameter Allowed Only through 13C. on 045/070 Units 2” 2” 2” 2” 3” 1-1/2” 2” TRANSITION TRANSITION *2” *2” INTAKE DO NOT transition DO NOT transition EXHAUST from smaller to larger from larger to smaller TOP VIEW pipe in horizontal runs...
  • Page 36 Follow the next two steps when installing the unit in Non- Direct Vent applications where combustion air is taken The A97DF2E / 97G2DFE furnace may be installed in from indoors and flue gases are discharged outdoors. either direct vent or non-direct vent applications. In...
  • Page 37 In accordance to CSA International B149 installation outdoors. The A97DF2E / 97G2DFE is then classified as a codes, the minimum allowed distance between the non-direct vent, Category IV gas furnace.
  • Page 38 Maximum Allowable Exhaust Vent Pipe Length (in ft.) without Insulation in Unconditioned Space for Winter Design Temperatures Unit Input Size Winter Design Temperatures ºF Vent Pipe (ºC) Diameter 1-1/2 in. 2 in. 32 to 21 (0 to -6) 2-1/2 in. 3 in.
  • Page 39 VENT TERMINATION CLEARANCES FOR DIRECT VENT INSTALLATIONS IN THE USA AND CANADA INSIDE CORNER DETAIL Fixed Operable Fixed Closed Closed Operable AREA WHERE TERMINAL AIR SUPPLY INLET VENT TERMINAL IS NOT PERMITTED US Installations Canadian Installations Clearance above grade, veranda, 12 inches (305mm) or 12 inches (305mm) 12 inches (305mm) or 12 inches (305mm) porch, deck or balcony...
  • Page 40 Details of Intake and Exhaust Piping 3” (76MM) MIN. SIZE PER EXHAUST PIPE Inches (MM) Terminations for Direct Vent Installations TERMINATION SIZE NOTE: In Direct Vent installations, combustion air is taken REDUCTION TABLE from outdoors and flue gases are discharged to outdoors. UNCONDITIONED ATTIC SPACE 8”...
  • Page 41 If intake and exhaust piping must be run up a side 1 1/2” (38mm) accelerator wall to position above snow accumulation or other provided on 71M80 & 44W92 EXHAUST obstructions, piping must be supported. At least one kits for -045 and -070 models VENT bracket must be used within 6”...
  • Page 42 VENT TERMINATION CLEARANCES FOR NON-DIRECT VENT INSTALLATIONS IN THE US AND CANADA INSIDE CORNER DETAIL Fixed Operable Fixed Closed Closed Operable AREA WHERE TERMINAL AIR SUPPLY INLET VENT TERMINAL IS NOT PERMITTED US Installations Canadian Installations Clearance above grade, veranda, 12 inches (305mm) or 12 inches (305mm) 12 inches (305mm) or 12 inches (305mm) porch, deck or balcony...
  • Page 43 Details of Exhaust Piping Terminations for Non- STRAIGHT-CUT OR * SIZE TERMINATION PIPE PER EXHAUST Direct Vent Applications ANGLE-CUT IN DIRECTION PIPE TERMINATION SIZE REDUCTION TABLE OF ROOF SLOPE * Exhaust pipes may be routed either horizontally through an outside wall or vertically through the roof. In attic or closet installations, vertical termination through the roof EXHAUST VENT Minimum 12”...
  • Page 44 FIELD FABRICATED WALL TERMINATION NOTE − FIELD−PROVIDED REDUCER MAY BE 2” (51mm) 3” (76mm) REQUIRED TO ADAPT LARGER VENT PIPE SIZE Vent Pipe Vent Pipe TO TERMINATION A− Minimum clearance above grade or average 12” (305 mm) 12” (305 mm) snow accumulation B−...

  • Page 45: Condensate Piping

    Heating cable kit is on the trap using a hose clamp. See Figure 38. available from Allied in various lengths; 6 ft. (1.8m) - kit no. 26K68 and 24 ft. (7.3m) - kit no. 26K69.
  • Page 46 Field Provided Vent 1” min. 2” max. above Trap can be installed a maximum condensate drain. of 5ft. from furnace (*PVC only) Condensate Drain Field Provided Vent Connection 1” min. 2” max. above condensate drain. 1” min. 2” max . 5’...
  • Page 47 Optional Condensate Drain Connection Adapter 3/4 inch slip X 3/4 inch mpt (not furnished) 90° Street Elbow 3/4 inch PVC (not furnished) Adapter 3/4 inch slip X 3/4 inch mpt (not furnished) Condensate Drain Connection In Unit 1 (25 mm) Min. Vent 2 (50 mm) Max.
  • Page 48 Optional Condensate Drain Connection Adapter 1/2 inch slip X 1/2 inch mpt (Not Furnished) 90° Street Elbow 1/2 inch PVC (Not Furnished) Adapter 1/2 inch slip X 1/2 inch mpt (Not Furnished) Condensate Drain Connection In Unit 1 (25 mm) Min. Vent 2 (50 mm) Max.

  • Page 49: Start-Up

    Remove the access panel. Move gas valve switch to OFF. See Figure 45. The gas valve on the A97DF2E / 97G2DFE is equipped Wait five minutes to clear out any gas. If you then with a gas control switch. Use only your hand to move the smell gas, STOP! Immediately call your gas supplier switch.

  • Page 50: Heating System Service Checks

    Heating System Service Checks 1/8 NPT PLUG C.S.A. Certification All units are C.S.A. design certified without modifications. GAS VALVE Refer to the A97DF2E / 97G2DFE Operation and Installation Instruction. Figure 46. Gas Piping When checking piping connections for gas leaks, use preferred means.
  • Page 51 NOTE: Pressure test adapter kit (10L34) is available from Furnace should operate at least 5 minutes before checking Allied to facilitate manifold pressure measurement. gas flow. Determine time in seconds for two revolutions of gas through the meter. (Two revolutions assures a more A manifold pressure post located on the gas valve provides accurate time.) Divide by two and compare to time in Table...
  • Page 52 Proper Combustion High Altitude Furnace should operate minimum 15 minutes with correct The manifold pressure, gas orifice and pressure switch manifold pressure and gas flow rate before checking may require adjustment or replacement to ensure proper combustion. See sections E- and F-. Take combustion operation at higher altitudes.
  • Page 53 Proper Ground and Voltage Measurement VAC Furnace Status A poorly grounded furnace can contribute to premature Expected Maximum ignitor failure. Use the following procedure to check for Power On Furnace Idle ground and voltage to the integrated control. CAI / Ignitor Enerigized 0.75 Indoor Blower Energized Less than 2...

  • Page 54: Typical Operating Characteristics

    0.5” W.C. OFF position. Seal the hole when the check is complete. Temperature Rise (Figure 48) Temperature rise for A97DF2E / 97G2DFE units depends EXTERNAL STATIC PRESSURE on unit input, blower speed, blower horsepower and static Supply Duct Static pressure as marked on the unit rating plate.

  • Page 55: Maintenance

    Maintenance Cabinet Width Filter Size 17-1/2” 16 x 25 x 1 (1) 21” Table 21. WARNING ELECTRICAL SHOCK, FIRE, Exhaust and Air Intake Pipes OR EXPLOSION HAZARD. Check the exhaust and air intake pipes and all connections Failure to follow safety warnings exactly could result in for tightness and to make sure there is no blockage.
  • Page 56 Winterizing and Condensate Trap Care Remove four burner box screws at the vestibule panel and remove burner box. Set burner box assembly 1. Turn off power to the furnace. aside. Have a shallow pan ready to empty condensate water. NOTE: If necessary, clean burners at this time. Follow Remove the clean out cap from the condensate trap procedures outlined in Burner Cleaning section.
  • Page 57 Cleaning the Burner Assembly (if needed) 26. Route heating component wiring through hole in blower deck and reinsert strain relief bushing. Turn off electrical and gas power supplies to furnace. Remove upper and lower furnace access panels. 27. Reinstall electrical junction box. Disconnect the 2-pin plug from the gas valve.

  • Page 58: Wiring Diagram

    Wiring Diagram 120V ACC HIGH HEAT LOW HEAT PARK UNIT HI COOL LOW COOL PRIMARY (IF USED) COMBUSTION AIR 045-12 BLACK BROWN BLUE YELLOW INDUCER MOTOR LIMIT VALVE 070-16 BLACK BLUE BROWN YELLOW 090-16 BLACK BLUE BROWN YELLOW S102 BURNERS 110-20 BLUE BROWN...

  • Page 59: Electronic Ignition

    The two-stage, variable speed integrated control used in sends a signal to begin an indoor blower 30-second A97DF2E / 97G2DFE units has an added feature of an ON-delay. When the delay ends, the indoor blower internal Watchguard control. The feature serves as an...
  • Page 60 Applications Using A Single-Stage Thermostat After the 20-second warm-up period has ended, the gas valve is energized on low fire (first stage) and See Figure 54 for ignition control sequence ignition occurs. At the same time, the control module sends a signal to begin an indoor blower 30-second B - Heating Sequence -- Integrated Control Thermostat ON-delay.

  • Page 61: Field Wiring Applications

    Field Wiring Applications Field Wiring Applications With Conventional Thermostat DIP Switch Settings and On-Board Links DIP Switch 1 On Board Links Must Be Cut To Select Thermostat Thermostat Wiring Connections System Options Heating Stages 1 Heat / 1 Cool FURNACE OUTDOOR T'STAT TERM.
  • Page 62 Field Wiring Applications with Conventional Thermostat (Continued) DIP Switch Settings and On-Board Links DIP Switch 1 On Board Links Must Be Cut To Select Thermostat Thermostat Wiring Connections System Options Heating Stages 2 Heat / 2 Cool FURNACE OUTDOOR T'STAT TERM.
  • Page 63 Field Wiring Applications with Conventional Thermostat (Continued) DIP Switch Settings and On-Board Links DIP Switch 1 Thermostat On Board Links Must Be Cut To Select Wiring Connections Thermostat Heating System Options Stages Dual Fuel L7724U FURNACE HEAT PUMP T'STAT TERM. STRIP Single Stage Heat Pump CUT ON-BOARD LINK...
  • Page 64 Field Wiring Applications with Conventional Thermostat (Continued) DIP Switch Settings and On-Board Links DIP Switch 1 Thermostat On Board Links Must Be Cut To Select Wiring Connections Thermostat Heating System Options Stages Dual Fuel FURNACE L7742U HEAT PUMP TERM. STRIP T'STAT Single Stage Heat Pump...

  • Page 65: Troubleshooting: Heating Sequence Of Operation

    Troubleshooting: Heating Sequence of Operation CALL FOR FIRST-STAGE HEAT CALL FOR 1ST STAGE HEAT (LOW FIRE) INDOOR BLOWER OFF AFTER HEAT FAN OFF DELAY (LOW HEAT SPEED) INDOOR LIMIT BLOWER OFF HIGH ERROR SWITCH INDOOR WATCHGUARD − AFTER HEAT FAN LIMIT SWITCH CODE CLOSED WITHIN 3...

  • Page 66: Troubleshooting: Heating Sequence Of Operation (Continued)

    Troubleshooting: Heating Sequence of Operation (Continued) CALL FOR SECOND-STAGE HEAT CALL FOR 2ND STAGE HEAT (HIGH FIRE) SINGLE STAGE 2 STAGE THERMOSTAT THERMOSTAT 2ND STAGE RECOGNITION DELAY ON DELAY (30 SECONDS) EXPIRED? EXPIRED? ONLY FOR 1ST REQUEST FOR 2ND STAGE HEAT INDUCER SWITCHED TO HIGH SPEED HIGH...

  • Page 67: Troubleshooting: Heating Sequence Of Operation (Continued)

    Troubleshooting: Heating Sequence of Operation (Continued) CALL FOR HEAT SATISFIED FIRST-STAGE HEAT SECOND-STAGE HEAT RUN MODE: 1ST OR 2ND STAGE CALL FOR HEAT. ALL INPUTS MONITORED (LIMIT, PRESSURE, CALL FOR HEAT/COOL, FLAME LEVEL) 2ND STAGE HEAT 2ND STAGE CALL FOR HEAT SATISFIED? DE−ENERGIZE 2ND STAGE GAS VALVE...

  • Page 68: Troubleshooting: Cooling Sequence Of Operation

    Troubleshooting: Cooling Sequence of Operation CALL FOR COOLING 1ST STAGE COOLING REQUEST RECEIVED WAIT FOR COMPRESSOR TIMED OFF DELAY TO EXPIRE ENERGIZE 1ST STAGE COOLING CONTACTOR (COMPRESSOR & FAN) INDOOR BLOWER SECOND ON DELAY ENERGIZE INDOOR BLOWER (LOW COOLING MODE) MAINTAIN INDOOR BLOWER (LOW COOLING MODE)

  • Page 69: Troubleshooting: Continuous Fan / Accessories Sequence Of Operation

    Troubleshooting: Continuous Fan / Accessories Sequence of Operation CALL FOR FAN CALL FOR FAN INDOOR BLOWER ON CONTINUOUS FAN SPEED CALL FOR FAN MAINTAIN INDOOR BLOWER AT REMOVED? CONTINUOUS FAN REQUEST MAINTAIN INDOOR FOR COOLING GO TO CALL FOR COOLING BLOWER AT RECEIVED? CONTINUOUS FAN...

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