Allied A96US2V Service Manual

Allied A96US2V Service Manual

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SERVICE MANUAL
A96US2V Gas Furnace
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.
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.
508148-01
WARNING
CAUTION

Table of Contents

Technical Specifications - A96US2V............................2
Parts Arrangement.......................................................6
Unit Components .........................................................7
Placement and Installation ........................................28
Joint Cementing Procedure .......................................29
Venting Practices .......................................................30
Vent Piping Guidelines ..............................................34
Condensate Piping ....................................................47
Start-Up .....................................................................52
Heating System Service Checks ...............................53
Proper Ground and Voltage .......................................56
Typical Operating Characteristics ..............................57
Maintenance ..............................................................58
Wiring and Sequence of Operation ...........................61
...................................................................................66
Program Unit Capacity Size Modes...........................70
Operation ...................................................................75
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.
*P508148-01*
Issue 2128
WARNING
(P) 508148-01
Page 1 of 75

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Summary of Contents for Allied A96US2V

  • 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 - A96US2V......2 Parts Arrangement............6 Unit Components ............7 Placement and Installation ........28...
  • Page 2: Technical Specifications - A96Us2V

    Technical Specifications - A96US2V MODEL NUMBER GUIDE A 96 U S 2 V 110 C 16 S - 01 A = Flagship Numeric Code 96 = 96% Efficiency S = Stainless Steel Heat Exchanger U = Upflow/Horizontal 12 = 3 Ton add on cooling...
  • Page 3 BLOWER PERFORMANCE DATA LOW FIRE HEATING - SCFM HIGH FIRE HEATING - SCFM [TEMP RISE: 20 - 50 F°]* [TEMP RISE: 35 - 65 F°]* Adj. -18% -12% Default +12% +18% +24% -18% -12% Default +12% +18% +24% 1008 1062 1116 A96US2V045B12S FIRST STAGE COOLING - SCFM...
  • Page 4 LOW FIRE HEATING - SCFM HIGH FIRE HEATING - SCFM [TEMP RISE: 35 - 65 F°]* [TEMP RISE: 60 - 90 F°]* Adj. -18% -12% Default +12% +18% +24% -18% -12% Default +12% +18% +24% 1005 1078 1152 1225 1299 1372 1446 1519...
  • Page 5 ACCESSORY LIST Catalog Number Description Comfort Sync Wi-Fi Thermostat 1.841197 Comfort Sync Wi-Fi Thermostat External Filter Rack Kits 1.841018 1 pack (16 x 25) 1.841039 10 pack (16 x 25) Natural to LP Kits 11K48 2-Stage – 90 11K47 High Altitude (> 7500') Return Air Base 68W62 17.5"...
  • Page 6: Parts Arrangement

    Parts Arrangement Figure 1. Page 6 of 75 Issue 2128 508148-01...
  • Page 7: Unit Components

    A 24V circuit breaker is also located in the control box. The switch provides overcurrent protection to the transformer A96US2V unit components are shown in Figure 1. (T1). The breaker is rated 3A at 32V. If the current exceeds The gas valve, combustion air inducer and burners can this limit the breaker will trip and all unit operation will be accessed by removing the access panel.
  • Page 8 NOTE: During abnormal conditions such as low supply Pin # Function voltage or low outdoor temperatures and the low fire Ignitor pressure switch does not close, the combustion air inducer Combustion Air Inducer High Speed will switch to high fire. After a 15 second pre-purge the Combustion Air Inducer Low Speed high fire pressure switch will close and the unit will begin operation on high fire.
  • Page 9 Figure 4. Integrated Control 508148-01 Issue 2128 Page 9 of 75...
  • Page 10 CLG BLOWER SPEED ADJUSTMENT 2ND STAGE HEAT ON DELAY DEFAULT 7 MIN UPSTAGE THERMOSTAT SELECTION DELAY + 10% TWO STAGE THERMOSTAT 12 MIN UPSTAGE − 10% DELAY 1−STAGE THERMOSTAT (TIMED STAGING) −SEE SW #2 HSI/CAI HEATING BLOWER−OFF DELAY 90 SECOND HTG BLOWER DIAGNOSTIC OFF DELAY...
  • Page 11 Display Action (when button released) No change (idle)* Remain in idle mode Solid “E” Enter diagnostic recall mode Solid “F” Enter flame signal mode Solid “P” (variable speed only) Program unit capacity/size unit (Unit Code) Soft disable Two horizontal bars * 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 4.
  • Page 12 Code Diagnostic Codes / Status of Equipment Action Required to Clear and Recover Idle mode (Decimal blinks at 1 Hertz - 0.5 • seconds ON, 0.5 seconds OFF). Cubic feet per minute (cfm) setting for indoor blower (1 second ON, 0.5 seconds OFF) / cfm setting for current mode displayed.
  • Page 13 Code Diagnostic Codes / Status of Equipment Action Required to Clear and Recover E180 Outdoor air temperature sensor failure. Only Compare outdoor sensor resistance to temperature resistance charts shown if shorted or out of range (Communicating in unit installation instructions. Replace sensor pack if necessary. At systems only) beginning of (any) configuration, furnace or air handler control will sense outdoor air and discharge air temperature sensor(s) If detected (reading...
  • Page 14 Code Diagnostic Codes / Status of Equipment Action Required to Clear and Recover E240 Low flame current - Run mode- Refer to Check micro-amperes of flame sensor using control diagnostics or field troubleshooting installed mode. Clean or replace sensor. Measure voltage of neutral to ground to ensure good unit ground.
  • Page 15 Code Diagnostic Codes / Status of Equipment Action Required to Clear and Recover E311 Heat rate reduced to match indoor blower airflow. Warning Only. Furnace blower in cutback mode due to restricted airflow. Reduce firing rate every 60 seconds to match available CFM. Check filter and duct system.
  • Page 16 Indoor Blower Operation DIP Switch Settings NOTE: All Comfort Sync settings are set at the Comfort Sync Wi-Fi thermostat. See Comfort Sync installation Switches 5 and 6 -- Cooling Mode Blower Speed -- instruction. In Comfort Sync communication system all The unit is shipped from the factory with the dip switches DIP switch and clippable link settings are ignored.
  • Page 17 Ramping Option A (Factory Selection) Heat Speed Switch 11 Switch 12 Switch 13 • Motor runs at 50% for 30 seconds. +24% • Motor then runs at 82% for approximately 7-1/2 +18% minutes. +12% • If demand has not been satisfied after 7-1/2 minutes, motor runs at 100% until demand is satisfied.
  • Page 18 • With Heat Pump - Cut W914 (R to DS) and W951 (R to O) on integrated control from cooling setpoint is 2°F. Table 11. Cooling Operating Sequence A96US2V and Single Stage Outdoor Unit Page 18 of 75 Issue 2128...
  • Page 19 • With Heat Pump - Cut W914 (R to DS) and W951 (R to O) on integrated control setpoint is 2°F. Table 12. Cooling Operating Sequence A96US2V and Two Stage Outdoor Unit 508148-01 Issue 2128 Page 19 of 75...
  • Page 20 IMPORTANT Earlier ECM motors used on other Allied Air furnace models are not interchangeable with motors used on the A96US2V furnace line. A solid-state controller is permanently attached to the motor.
  • Page 21 The cfm remains relatively stable over a broad range of static pressure. Since the blower constantly adjusts rpm to A choke coil is used on A96US2V 4 and 5 ton units maintain a specified cfm, motor rpm is not rated. Hence, equipped with 1 hp motors.
  • Page 22 Using test jumpers, apply 24V to pins 3 and 4 on P49 P48 5 Pin on the motor. P49 4 Pin NOTE: Do not apply 24V to pins 2 and 4 on P49. Doing SHAFT so will cause permanent damage to the motor. Motor should run at 75%.
  • Page 23 13 for ignitor location and Figure 15 for ignitor check out. Measure the resistance between each of the three motor leads (3-pin plug) and the unpainted part of the end shield. NOTE: The A96US2V furnace contains electronic components that are polarity sensitive. Make sure that the If the winding resistance to ground is <100k ohms, replace...
  • Page 24 Each burner uses an orifice LPG change over kits are available from Allied. Kits include that is precisely matched to the burner input. Burners can burner orifices and a gas valve.
  • Page 25 Header Box pressure) and opens the circuit to the furnace control and All A96US2V units use a two-stage combustion air inducer gas valve. A bleed port on the switch allows relatively to move air through the burners and heat exchanger during dry air in the vestibule to purge switch tubing, to prevent heating operation.
  • Page 26 Test 1 Check ignitor circuit for correct resistance. Remove 4-pin plug from control. Check ohms reading across terminals 1 and 5. Reading should be between 39 and 70 ohms. 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 27 Pressure Switch Check Operate unit and observe manometer reading. Readings will change as heat exchanger warms. To check pressure switch differential, refer to Figure 16 Take one reading immediately after start-up. and use the provided fittings and tubing to follow the steps below.
  • Page 28: Placement And Installation

    ASTM PRIMER & SOLVENT CEMENT IMPORTANT SPECIFICATION PVC & CPVC Primer F656 A96US2V exhaust and intake connections are made PVC Solvent Cement D2564 of PVC. Use PVC primer and solvent cement when CPVC Solvent Cement F493 using PVC vent pipe. When using ABS vent pipe, use...
  • Page 29: Joint Cementing Procedure

    STANDARD CONCENTRIC Outdoor Outdoor Exhaust Exhaust Flush 1-1/2” 2” 3” Accelerator VENT PIPE Accelerator Mount Concentric Concentric Concentric (Dia. X A96USMV DIA. (Dia. X Length) (in.) Length) 71M80 69M29 60L46 1-1/2” X 12” 2” X 12” 51W11 * or 44W93+ +44W92++ +44W92++ 1-1/2...
  • Page 30: Venting Practices

    Removal of the Furnace from Common Vent Immediately after applying last coat of cement to pipe, and while both inside socket surface and end of pipe are wet with cement, forcefully insert end of pipe into WARNING socket until it bottoms out. Turn PVC pipe 1/4 turn during assembly (but not after pipe is fully inserted) to CARBON MONOXIDE POISONING HAZARD distribute cement evenly.
  • Page 31 Turn on clothes section. dryers and any appliances not connected to the The A96US2V is designed for combustion air intake common venting system. Turn on any exhaust fans, through an inlet in the unit’s top cap. Intake air piping is such as range hoods and bathroom exhausts, so they independent of exhaust piping.
  • Page 32 1. Use field-provided materials and the factory-provided air intake screen to route the intake piping as shown in The A96US2V furnace may be installed in either direct Figure 21 or Figure 22. Maintain a minimum clearance vent or non-direct vent applications. In non-direct vent of 3”...
  • Page 33 TYPICAL INTAKE PIPE CONNECTIONS IN UPFLOW DIRECT OR NON-DIRECT VENT APPLICATIONS 2” 3” Pipe size determined in Table 5 TRANSITION INTAKE *2” 2” 2” 2” 2” * 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.
  • Page 34: Vent Piping Guidelines

    Inlet Air Roof Terminated (Minimum 12 in. Exhaust Pipe (305mm) above The A96US2V can be installed as either a Non-Direct Attic Floor) Vent or a Direct Vent gas central furnace. NOTE: In Non-Direct Vent installations, combustion air *Intake Debris Screen...
  • Page 35 Use the following steps to correctly size vent pipe diameter. Exhaust Pipe 12” Min. 12” Max. Horizontal 045, 070, Gas Furnace Furnace capacity? 090, 110 or 135 btuh NOTE - Standard or ward unit. A minimum of 1/4” (6mm) drop for each 12” (305mm) Which termination? Concentric? of horizontal run is mandatory for drainage.
  • Page 36 Maximum Allowable Intake or Exhaust Vent Length in Feet Standard Termination at Elevation 0 - 4500 ft Number 1-1/2" Pipe 2" Pipe 2-1/2" Pipe 3" Pipe of 90° Model Model Model Model Elbows Used Standard Termination Elevation 4500 - 10,000 ft 1-1/2"...
  • Page 37 Maximum Allowable Intake or Exhaust Vent Length in Feet Concentric Termination at Elevation 0 - 4,500 ft Number 1-1/2" Pipe 2" Pipe 2-1/2" Pipe 3" Pipe of 90° Model Model Model Model Elbows Used Concentric Termination Elevation 4,501 - 10,000 ft 1-1/2"...
  • Page 38 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 0 - 4500 ft Number 1-1/2" Pipe 2" Pipe 2-1/2" Pipe 3" Pipe of 90°...
  • Page 39 In Direct Vent applications, combustion air is taken from outdoors and the flue gases are discharged to the outdoors. The A96US2V is then classified as a direct vent, Category IMPORTANT IV gas furnace. For Canadian Installations Only:...
  • Page 40 Maximum Allowable Exhaust Vent Pipe Length (in ft.) without Insulation in Unconditioned Space for Winter Design Temperatures Winter Design Unit Input Size Temperatures ºF Vent Pipe (ºC) Diameter 1-1/2 in. 32 to 21 2 in. (0 to -6) 2-1/2 in. 3 in.
  • Page 41 ‡ Permitted only if veranda, porch, deck or balcony is fully open on a minimum of two sides beneath the floor. Allied Air recommends avoiding this location if possible. Figure 28. Vent Termination Clearances Direct Vent Installations...
  • Page 42 Details of Intake and Exhaust Piping Intake and exhaust pipes should be placed as close together as possible at termination end (refer to Terminations for Direct Vent Installations illustrations). Maximum separation is 3” (76MM) NOTE: In Direct Vent installations, combustion air is taken on roof terminations and 6”...
  • Page 43 On field-supplied terminations, a minimum distance STRAIGHT-CUT OR between the end of the exhaust pipe and the end of ANGLE-CUT IN DIRECTION OF ROOF SLOPE * the intake pipe without a termination elbow is 8” and a minimum distance of 6” with a termination elbow. See 3”...
  • Page 44 ‡ Permitted only if veranda, porch, deck or balcony is fully open on a minimum of two sides beneath the floor. Allied Air recommends avoiding this location if possible. Figure 37. Vent Termination Clearances...
  • Page 45 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 EXHAUST VENT Minimum 12”...
  • Page 46 FIELD FABRICATED WALL TERMINATION NOTE − FIELD−PROVIDED REDUCER MAY BE 2” (51mm) 3” (76mm) REQUIRED TO ADAPT Vent Pipe Vent Pipe LARGER VENT PIPE SIZE TO TERMINATION A− Minimum clearance above grade or average 12” (305 mm) 12” (305 mm) snow accumulation B−...
  • Page 47: Condensate Piping

    Determine which side condensate piping will exit the Condensate Piping unit, location of trap, field-provided fittings and length of PVC pipe required to reach available drain. This unit is designed for either right- or left-side exit of For furnaces with a 1/2” drain connection use a 3/8 condensate piping in upflow applications.
  • Page 48 line should be routed within the conditioned space to avoid freezing of condensate and blockage of drain line. If this is not possible, a heat cable kit may be used on the condensate trap and line. Heating cable kit is available in various lengths;...
  • Page 49 Evaporator drain From Evaporator Coil line required Field Provided Vent 1” min. 2” max. above (Trap at coil is optional) condensate drain. Field-Provided Vent (1” min. to 2” Max.above condensate drain connection) Furnace Condensate Condensate Drain Condensate Drain Connection Optional Overflow Switch Figure 47.
  • Page 50 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 51 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 52: Start-Up

    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 A96US2V is equipped with a gas control switch. Use only your hand to move the switch.
  • Page 53: Heating System Service Checks

    All units are CSA design certified without modifications. Move gas valve switch to OFF. See Figure 51. Refer to the A96US2V Installation Instruction. Wait five minutes to clear out any gas. If you then smell gas, STOP! Immediately call your gas supplier Gas Piping from a neighbor’s phone.
  • Page 54 Proper Gas Flow (Approximate) When checking piping connections for gas leaks, use preferred means. Kitchen detergents can cause harmful Furnace should operate at least 5 minutes before checking corrosion on various metals used in gas piping. Use of a gas flow. Determine time in seconds for two revolutions of specialty Gas Leak Detector is strongly recommended.
  • Page 55 See Table 24 for manifold pressures. See Table 25 for gas conversion and pressure switch kits. Supply Line Manifold Pressure in w.g. Pressure in w.g. A96US2V 0 - 4500 ft. 4501 - 5500 ft. 5501 - 6500ft. 6501 - 7500ft.
  • Page 56: Proper Ground And Voltage

    Proper Ground and Voltage In addition, measure the AC voltage from Line Hot A poorly grounded furnace can contribute to premature ignitor failure. Use the following procedure to check for to Line Neutral (spade terminals) on the integrated control. See Figure 53. This voltage should be in the ground and voltage to the integrated control.
  • Page 57: Typical Operating Characteristics

    Temperature Rise more than 1.0” W.C. Temperature rise for A96US2V units depends on unit input, Seal the hole when the check is complete. blower speed, blower horsepower and static pressure as marked on the unit rating plate.
  • Page 58: Maintenance

    Filter Size Maintenance Furnace Cabinet Width Side Return Bottom Return 17-1/2” 16 x 25 x 1 (1) 16 x 25 x 1 (1) 21” 20 x 25 x 1 (1) WARNING 24-1/2” 16 x 25 x 1 (2) 24 x 25 x 1 (1) ELECTRICAL SHOCK, FIRE, OR EXPLOSION Table 27.
  • Page 59 Condensate Hose Screens (Figure 56) 10. Disconnect condensate drain line from the cold end header box. Check the condensate hose screens for blockage and clean if necessary. 11. Disconnect condensate drain tubing from flue collar. Remove screws that secures the flue collar into place. Turn off power to the unit.
  • Page 60 Cleaning the Burner Assembly 30. Reinstall the cold end header box. Turn off electrical and gas power supplies to furnace. 31. Reinstall the combustion air inducer. Reconnect the Remove upper and lower furnace access panels. plug to the wire harness. Disconnect the wires from the gas valve.
  • Page 61: Wiring And Sequence Of Operation

    Wiring and Sequence of Operation Figure 57. Field Wiring Diagram 508148-01 Issue 2128 Page 61 of 75...
  • Page 62 The two-stage, variable speed integrated control used furnace will switch to low fire (first-stage). in A96US2V units has an added feature of an internal Watchguard control. The feature serves as an automatic At the end of the recognition delay, the integrated...
  • Page 63 NOTE: In these applications, two-stage heat will be After the 20-second warm-up period has ended, the gas valve is energized on low fire (first stage) and initiated by the integrated control if heating demand has ignition occurs. At the same time, the control module not been satisfied after the field adjustable period (7 or 12 minutes).
  • Page 64 Comfort Sync Wifi Thermostat with A96US2V Comfort Sync Wifi Thermostat with A96US2V and Comfort Sync-enabled Outdoor Unit and Non-Communicating Outdoor Unit Comfort Sync Wifi Thermostat Comfort Sync Wifi Thermostat Comfort Sync-enabled A96US2V Indoor Furnace Comfort Sync-enabled A96US2V Indoor Furnace Comfort Sync-enabled Outdoor Air Conditioner or Heat Pump...
  • Page 65 NOTE: COMFORT SYNC WIFI THERMOSTAT SENSE HUMIDITY & CONTROLS HUM CONTACTS TO CYCLE HUMIDIFIER BASED ON 120V CONNECTIONS DEMAND. NO OTHER CONTROL OR HUMIDISTAT REQUIRED. “HUM” CONTACT IS OPTIONAL OUTDOOR AIR SENSOR FOR USE WITH HUMIDIFIER CLOSED ANYTIME (IF NOT ALREADY IN THE SYSTEM FOR OTHER FUNCTIONS. HUMIDITY DEMAND IS PRESENT BUILT INTO ALL COMFORT SYNC OUTDOOR UNITS).
  • Page 66: Field Wiring Applications With Conventional Thermostat

    ON - 12 minutes *Not required on all units NOTE - Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the A96US2V integrated control. Table 28. Field Wiring for Non-Communicating Thermostat Applications...
  • Page 67 2 Heat / 1 Cool *Not required on all units NOTE - Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the A96US2V integrated control. Table 28. Field Wiring for Non-Communicating Thermostat Applications...
  • Page 68 PUMP out blue outdoor sensor NOTE - Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the A96US2V integrated control. Table 28. Field Wiring for Non-Communicating Thermostat Applications Page 68 of 75...
  • Page 69 DEHUM out blue mode outdoor sensor NOTE - Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the A96US2V integrated control. Table 28. Field Wiring for Non-Communicating Thermostat Applications 508148-01 Issue 2128...
  • Page 70: Program Unit Capacity Size Modes

    Program Unit Capacity Size Modes Power-Up - Number displayed by integrated control represents unit size code (furnace model and capacity). If three horizontal bars are displayed followed by continuous E203, furnace control does not recognize unit size code. Configure per the following: Turn room thermostat to OFF.
  • Page 71: 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 72 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 73 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 74: 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 2 SECOND ON DELAY ENERGIZE INDOOR BLOWER (LOW COOLING MODE) MAINTAIN INDOOR BLOWER (LOW COOLING MODE)
  • Page 75: Troubleshooting: Continuous Fan Sequence Of Operation

    Troubleshooting: Continuous Fan 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 MAINTAIN INDOOR...

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