Service Instructions TM 34.5" Chassis ACVC96/AMVC96 GCVC96/GMVC96 Gas Furnaces This manual is to be used by qualified, professionally trained HVAC technicians only. Goodman does not assume any responsibility for property damage or personal injury due to improper service procedures or services performed by an unqualified person.
TABLE OF CONTENTS IMPORTANT INFORMATION ..................................... 2 - 5 PRODUCT IDENITIFICATION .................................. 6 - 10 TROUBLESHOOTING ........................................... 45 - 50 ACCESSORIES .................................................... 11 - 13 SERVICING .......................................................... 57 - 75 INSTALLATION CONSIDERATIONS ...................... 14 - 39 MAINTENANCE ...................................................
IMPORTANT INFORMATION Special Warning for Installation of Furnace or Air Handling Units in Enclosed Areas such as Garages, Utility Rooms or Parking Areas Carbon monoxide producing devices (such as an automobile, space heater, gas water heater, etc.) should not be operated in enclosed areas such as unventilated garages, utility rooms or parking areas because of the danger of carbon monoxide (CO) poisoning resulting from the exhaust emissions.
IMPORTANT INFORMATION FOR YOUR SAFETY READ BEFORE OPERATING If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or loss of life. A. This appliance does not have a pilot. It is equipped with an ignition device which automatically lights the burners. Do not try to light the burners by hand. B. BEFORE OPERATING smell around the appliance area for gas.
IMPORTANT INFORMATION CONSIGNES DE SECURITE - LIRE AVANT D'ALLUMER L'APPAREIL INSTRUCTIONS DE SERVICE AVERTISSEMENT: Le non-respect des instructions qui suivent peut ^ entrainer un risque d'incendie ou d'explosion causant des dommages, des blessures ou la mort. A. Cet appareil comporte pas de veilleuse. Il est muni d'un mecanisme qui allume ^ ^ manuellement. automatiquement le bruleur. N'allumez paz le bruleur B. Sentir tout autour de l'appariel AVANT D'ALLUMER afin de deceler toute fuite de gaz.
PRODUCT IDENTIFICATION The model and manufacturing number are used for positive identification of component parts used in manufacturing. Please use these numbers when requesting service or parts information.
PRODUCT IDENTIFICATION MODEL: GMVC96 REV AA MODEL: GCVC96 REV AA Equipment Type Goodman Brand Residential Gas Furnace Heating Stages Two Equipment Type Goodman Brand Residential Gas Furnace Cooling Stages Two Heating Stages Two Control Type ClimateTalk ™ or Conventional 24 Volt Cooling Stages Two Control Type Blower Motor Type 4 Wire Variable Speed ECM ClimateTalk ™ or Conventional 24 Volt Blower Motor Type 4 Wire Variable Speed ECM GMVC96 Installation Positions 0403BN 0603BN 0803
PRODUCT IDENTIFICATION MODEL # MFG # AFE18-60A AMU1620 AMU1625 AMU2020 AMU2025 GMU1620 GMU1625 GMU2020 GMU2025 ASAS-10 ASAS-11 ASAS-12 ASAS-18 CFSB17 CFSB21 CFSB24 CTK01AA CTK01BA 8 N/A P1251305F P1251306F P1251307F P1251308F N/A DESCRIPTION Fossil Fuel Kit. The AFE18-60A control is designed for use where the indoor coil is located above/downstream of a gas or fossil fuel furnace when used with a heat pump. It will operate with single and two stage heat pumps and single and two stage furnaces.
PRODUCT IDENTIFICATION MODEL # CTK02** CTK03AA CTK03AB CTK04 MFG # CTK02** DESCRIPTION Communicating Thermostat Kit- Digitally communicating thermostat. Designed for use with compatible Amana® Brand or Goodman® Brand Air Handlers or Furnaces and outdoor split AC or Heat Pump units.
PRODUCT IDENTIFICATION MODEL # DESCRIPTION N/A External Filter Rack Kit. For use with Goodman® and Amana® Brand 90% upflow variable speed gas furnace models. This kit is intended to provide a location, external to the furnace casing, for installation of a permanent filter. The rack is mounted over the indoor air blower compartment area of either side panel, and provide filter retention as well as a location for attaching return air ductwork. N/A High Altitude Natural Gas Kit.
ACCESSORIES 96% Com Furnace Accessories Mode l Numb e r AFE18 0 - 6 0 A AMU / G MU EFR0 2 AS AS / G S AS CF S B17 CF S B2 1 CFS B2 4 RF0 0 0 14 2 De sc ription F ossil Fue l Kit Me dia Air Cle a n e rs Exte rna l Filte r Ra c k Ele c tronic Air Cle a n e r Downflow S u bba se 17 . 5 " Downflow S ub ba se 2 1" Downflow S ub ba se 24.
ACCESSORIES SLOTS IN FILTER CLEAR SCREWS ON UNIT EXTERNAL FILTER RACK (EFR02) BLOWER DECK SCREWS 96% Upflow Model Furnaces UNIT SIDE PANEL FRONT OF UNIT FILTER RACK ASSEMBLY (FACE FILTER OPENING TOWARDS FRONT OF UNIT) BASE OF UNIT RETURN AIR CUTOUT AREA LOWER EDGE SCREW SIDE WALL VENT KITS (0170K00000S) (0170K00001S) Description 0170K00000S This side wall only vent kit #0170K00000S is to be used with 2” - 3” vent systems.
ACCESSORIES CONCENTRIC VENT CONVERSION KIT The CVENT-2 (DCVK20) (2") or the CVENT-3 (DCVK-30) (3") is a concentric vent kit approved with furnaces listed in this manual. This concentric vent kit allows for vertical or horizontal vent termination. The illustrations give a brief view of the kit and its application. See the section in this manual under "Vent Flue and Combustion Air Pipe Terminations" for more information or consult the Installation and Operating Instructions (IO-619*).
INSTALLATION CONSIDERATIONS Safety Please adhere to the following warnings and cautions when installing, adjusting, altering, servicing, or operating the furnace. WARNING TO PREVENT PERSONAL INJURY OR DEATH DUE TO IMPROPER INSTALLATION, ADJUSTMENT, ALTERATION, SERVICE OR MAINTENANCE, REFER TO THIS MANUAL. FOR ADDITIONAL ASSISTANCE OR INFORMATION, CONSULT A QUALIFIED INSTALLER, SERVICE AGENCY OR THE GAS SUPPLIER.
INSTALLATION CONSIDERATIONS National Fire Protection Association 1 Batterymarch Park Quincy, MA 02269 The rated heating capacity of the furnace should be greater than or equal to the total heat loss of the area to be heated. The total heat loss should be calculated by an approved method or in accordance with “ASHRAE Guide” or “Manual J-Load Calculations” published by the Air Conditioning Contractors of America.
INSTALLATION CONSIDERATIONS • • If the furnace is installed in a residential garage, position the furnace so that the burners and ignition source are located not less than 18 inches (457 mm) above the floor. Protect the furnace from physical damage by vehicles. If the furnace is installed horizontally, the furnace access doors must be vertical so that the burners fire horizontally into the heat exchanger. Do not install the unit with the access doors on the “up/top” or “down/ bottom” side of the furnace.
INSTALLATION CONSIDERATIONS If resizing is required on any portion of the venting system, use the appropriate table in Appendix G in the latest edition of the National Fuel Gas Code ANSI Z223.1 and/or CSA B149 Installation Codes. Thermostat Requirements The optional CTK0*** thermostat kit may be used with ComfortNet™ compatable furnaces (ACVC, AMVC, GCVC, GMVC models). Refer to System Operation - ComfortNet™ System for details.
INSTALLATION CONSIDERATIONS Most homes will require outside air be supplied to the furnace area by means of ventilation grilles or ducts connecting directly to the outdoors or spaces open to the outdoors such as attics or crawl spaces. The following information on air for combustion and ventilation is reproduced from the National Fuel Gas Code NFPA 54/ANSI Z223.1 Section 9.3. 9.3* Air for Combustion and Ventilation.
INSTALLATION CONSIDERATIONS (1)*Where directly communicating with the outdoors or where communicating to the outdoors through vertical ducts, each opening shall have a minimum free area of 1 in.2/4000 Btu/hr (550 min2/kW) of total input rating of all appliances in the enclosure. [See Figure A.9.3.3.1(1)(a) and Figure A.9.3.3.1(1)(b).
INSTALLATION CONSIDERATIONS (c) The minimum size of outdoor opening(s) shall be the full size of outdoor opening(s) calculated in accordance with 9.3.3, multiplied by the reduction factor. The minimum dimension of air openings shall not be less than 3 in. (80 mm). 9.3.8.4 Ducts shall not serve both upper and lower combustion air openings where both such openings are used. The separation between ducts servicing upper and lower combustion air openings shall be maintained to the source of combustion air. 9.
Installation Positions *MVC96 models may be installed up flow or horizontally with left or right side down. *CVC96 models may be installed down flow or horizontally with left or right side down. Do not install any furnace on its back. Horizontal Installations 1. Horizontal installations require 5.5" under the furnace to accommodate the drain trap. 2. Horizontal furnaces must be installed with ¾” slope from back to front to permit condensate flow towards the front of the furnace.
INSTALLATION CONSIDERATIONS Alternate Electrical and Gas Line Connections The furnaces have provisions allowing for electrical and gas line connections through either side panel. In horizontal applications the connections can be made either through the “top” or “bottom” of the furnace. WARNING UPON COMPLETION OF THE FURNACE INSTALLATION, CAREFULLY INSPECT THE ENTIRE FLUE SYSTEM BOTH INSIDE AND OUTSIDE THE FURNACE TO ASSURE IT IS PROPERLY SEALED.
INSTALLATION CONSIDERATIONS NOTE: This provision does not apply to the combustion air intake termination of a direct vent application. • The vent termination of a non-direct vent application must terminate at least 4 feet below, 4 feet horizontally from, or 1 foot above any door, window, or gravity air inlet into any building.
INSTALLATION CONSIDERATIONS Horizontal vent/flue pipe terminations should be as shown in the following figure. Refer to Vent/Flue Pipe and Combustion Air Pipe - Termination Locations section in this manual or the installation instructions for details concerning location restrictions. A 2 3/8" diameter wall penetration is required for 2" diameter pipe while a 3 1/2" diameter hole is required for 3" diameter pipe.
INSTALLATION CONSIDERATIONS 1) Maximum allowable limits listed on individual lengths for inlet and flue and NOT a combination. 2) Minimum requirement for each vent pipe is five (5) feet in length and one elbow/tee. 3) Tee used in the vent/flue termination must be included when determining the number of elbows in the piping system. 90° ELBOWS 4) 2 1/2” or 3” diameter pipe can be used in place of 2” diameter pipe. 5) Increased Clearance Configurations using (2) 45 deg.
INSTALLATION CONSIDERATIONS Condensate Drain Lines and Drain Trap A condensing gas furnace achieves its high level of efficiency by extracting heat from the products of combustion to the point where condensation takes place. The condensate must be collected in the furnace drain trap and routed to an appropriate drain location in compliance with local and national codes. 90° ELBOWS 3”-24” BETWEEN PIPES AIR INTAKE SCREEN (OPTIONAL) 12" MIN.
INSTALLATION CONSIDERATIONS Inlet gas supply pressures must be maintained within the ranges specified below. The supply pressure must be constant and available with all other household gas fired appliances operating. The minimum gas supply pressure must be maintained to prevent unreliable ignition. The maximum must not be exceeded to prevent unit overfiring. INLET GAS SUPPLY PRESSURE Natural Gas Minimum: 4.5" w.c. Maximum: 10.0" w.c. Propane Gas Minimum: 11.0" w.c. Maximum: 13.0" w.c.
INSTALLATION CONSIDERATIONS 4. Install a drip leg to trap dirt and moisture before it can enter the gas valve. The drip leg must be a minimum of three inches long. GAS PIPING CONNECTIONS CAUTION TO AVOID POSSIBLE UNSATISFACTORY OPERATION OR EQUIPMENT DAMAGE DUE TO UNDERFIRING OF EQUIPMENT, USE THE PROPER SIZE OF 5. Install a 1/8" NPT pipe plug fitting, accessible for test gage connection, immediately upstream of the gas supply connection to the furnace.
INSTALLATION CONSIDERATIONS GAS PIPING CHECKS Before placing unit in operation, leak test the unit and gas connections. WARNING TO AVOID THE POSSIBLITY OF EXPLOSION OR FIRE, NEVER USE A MATCH OR OPEN FLAME TO TEST FOR LEAKS. Check for leaks using an approved chloride-free soap and water solution, an electronic combustible gas detector, or other approved testing methods. NOTE: Never exceed specified pressures for testing.
INSTALLATION CONSIDERATIONS WARNING IF THE INFORMATION IN THESE INSTRUCTIONS IS NOT FOLLOWED EXACTLY, A FIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE. – DO NOT STORE OR USE GASOLINE OR OTHER FLAMMABLE VAPORS AND LIQUIDS IN THE VICINITY OF THIS OR ANY OTHER APPLIANCE. – WHAT TO DO IF YOU SMELL GAS: • DO NOT TRY TO LIGHT ANY APPLIANCE.
INSTALLATION CONSIDERATIONS Use a separate fused branch electrical circuit containing properly sized wire, and fuse or circuit breaker. The fuse or circuit breaker must be sized in accordance with the maximum overcurrent protection specified on the unit rating plate. An electrical disconnect must be provided at the furnace location. NOTE: Line polarity must be observed when making field connections.
HUM-IN NEUTRAL HUM-OUT INSTALLATION CONSIDERATIONS 24 VOLT HUMIDIFIER A 24 volt hum circuit may be powered off of the n/c side of the low fire pressure. If added in the field, the wiring must conform to all local and national codes. Connect the COM side of the humidifier to the C terminal on the furnace control board (or to the COM side of the 24 VAC transformer). Do not connect 115V humidifier to these terminals.
INSTALLATION CONSIDERATIONS Thermostat Wiring - Two-Stage Variable Speed ComfortNet™ Furnaces As a two-stage non-communicating furnace, the furnace integrated control module provides terminals for both “W1” and “W2”, and “Y1” and “Y2” thermostat connections. This allows the furnace to support the following system applications: ‘Two-Stage Heating Only’, ‘Two-Stage Heating with Single Stage Cooling’, and ‘Two-Stage Heating with TwoStage Cooling’.
INSTALLATION CONSIDERATIONS CFM CHART Model *M VC960403BN* *MVC960603BN* *MVC960803BN* *MVC960804CN* *MVC961005CN* *MVC961205DN* *CVC960403BN* *CVC960603BN *CVC960803BN *CVC960804CN* *CVC961005CN* *CVC961205DN* Tap A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D A B C D Low High Low High Stage Stage Stage Stage Cool Cool Heat Heat 403 527 675 803 398 557 696 810 403 540 705 819 513 660 791 913 564 784 982 1259 547 831 1020 1278 449 569 716 85
INSTALLATION CONSIDERATIONS DIP SWITCHES - FURNACES EQUIPPED WITH PCBKF103 / PCBKF104 Switch Bank S1 S3 S4 S5 Purpose Function 90 120 Heating Off Delay 150 180 2 Stage Stat Thermostat 2 Stage Stat Setup 1 Stg Stat 5 min delay 1 Stg Stat auto delay A B Cooling Airflow C D Add 5% Minus 5% Trim Add 10% Minus 10% A B Ramping Profile C D A B Heating Airflow C D Disabled Dehum Enabled Disabled Trim Enabled 25% 50% Continuous Fan 75% 100% 1 Off On Off On Off On Off On Off On Off On Dip Switch 2 3 Off O
INSTALLATION CONSIDERATIONS Single-Stage Thermostat Application A single-stage thermostat with only one heating stage may be used to control this furnace. The application of a singlestage thermostat does not offer “true” thermostat-driven twostage operation, but provides a timed transition from low to high fire. The furnace will run on low stage for a fixed period of time before stepping up to high stage to satisfy the thermostat’s call for heat.
INSTALLATION CONSIDERATIONS Example: Cooling Capacity of 30,000 BTU/hr. 30,000/12,000 = 2.5 Tons 2. Determine the proper air flow for the cooling system. Most cooling systems are designed to work with air flows between 350 and 450 CFM per ton. Most manufacturers recommend an air flow of about 400 CFM per ton. Example: 2.5 tons X 400 CFM per ton = 1000 CFM The cooling system manufacturer’s instructions must be checked for required air flow.
INSTALLATION CONSIDERATIONS SIDE RETURN BOTTOM RETURN Cabinet Width (In.) Nominal Filter Size (In.) Approx. Flow Area (In.) Cabinet Width (In.) All 16x25x1 400 14" 14X25X1 350 17-1/2 21 24-1/2 14X25X1 16x25x1 20X25X1 350 400 500 Nominal Approx. Filter Flow Area Size (In.) (In.) Refer to Minimum Filter Area tables to determine filter area requirement. NOTE: Filters can also be installed elsewhere in the duct system such as a central return.
INSTALLATION CONSIDERATIONS COUNTERFLOW FILTER INSTALLATION This furnace has provisions for the installation of return air filters at the counterflow top return.
SYSTEM OPERATION NORMAL SEQUENCE OF OPERATION POWER UP The normal power up sequence is as follows: • 115 VAC power applied to furnace. • Integrated control module performs internal checks. • Integrated control module displays 8 8 on dual 7-segment display LED’s. • Integrated control module monitors safety circuits continuously. • Furnace awaits call from thermostat. Dual 7-segment LED’s display ON while awaiting call from thermostat.
SYSTEM OPERATION FAN ONLY MODE The normal operational sequence in fan only mode is as follows: • R and G thermostat contacts close, initiating a call for fan. • Integrated control module performs safety circuit checks. • Circulator blower is energized on continuous fan speed following a five (5) second delay. Electronic air cleaner terminal is energized. • Circulator blower runs, integrated control module monitors safety circuits continuously. • R and G thermostat contacts open, completing the call for fan.
SYSTEM OPERATION the gas valve will be de-energized and another purge will occur and a third ignitor warm up for an additional (2) seconds will occur. The control will cycle the gas valve a total of three (3) times before it determines it cannot establish measurable combustion and enters a locked out state. The diagnostic error code for this problem is E0.
SYSTEM OPERATION NOTE: Turn off power to the furnace prior to inserting memory card onto the control. With memory card inserted onto control, turn power to furnace on. Control has accepted memory card data once control displays ON on the dual, 7-segment display. Memory card may be left on control or removed and used on another furnace of the same model. Turn power off to furnace prior to removing memory card. 15. ECM Blower Motor Not Running.
SYSTEM OPERATION 22. Motor Parameters. This condition occurs if the motor does not receive all the information is requires to operate or an event occurs that prevents the motor from running, or the motor fails to start for (40) consecutive attempts. The diagnostic error code for the this condition is b7. Probable causes are intermittent wiring connection between the control and motor, an error with the furnace control, or any of the conditions described in 19, 20, or 21 above. 23. Low Indoor Airflow.
TROUBLESHOOTING Symptoms of Abnormal Diagnostic/ Status LED Operation (Legacy & Codes ComfortNet™ Thermostat) Fault Description • No 115 power to furnace or no 24 volt power to integrated control module • Blown fuse or circuit breaker • Integrated control module has an internal fault ComfortNet™ Thermostat Only Message Code INTERNAL FAULT EE Possible Causes Corrective Actions Notes & Cautions • Manual disconnect switch OFF, door switch open or 24 volt wire improperly connected or loose • Blown fuse
TROUBLESHOOTING Symptoms of Abnormal Operation (Legacy & ComfortNet™ Thermostat) Diagnostic/ Status LED Codes Fault Description ComfortNet™ Thermostat Only Message Code Possible Causes Corrective Actions Notes & Cautions • Induced draft blower runs continuously with no further furnace operation. • Integrated control module LED display provides E2 error code. • ComfortNet™ thermostat “Call for Service” icon illuminated. • ComfortNet™ thermostat scrolls “Check Furnace” message.
TROUBLESHOOTING Symptoms of Abnormal Operation (Legacy & ComfortNet™ Thermostat) Diagnostic/ Status LED Codes Fault Description ComfortNet™ Thermostat Only Possible Causes Message Code IGNITER FAULT E7 • Improperly connected igniter. • Shorted igniter. • Poor unit ground. • Igniter relay fault on integrated control module. Corrective Actions • Check and correct wiring from integrated control module to igniter. • Replace shorted igniter. • Check and correct unit ground wiring.
TROUBLESHOOTING Symptoms of Abnormal Diagnostic/ Operation (Legacy Status LED Fault Description & ComfortNet™ Codes Thermostat) ComfortNet™ Thermostat Only Message Code Possible Causes Corrective Actions Notes & Cautions • Verify shared data set is • Turn power OFF prior to repair correct for the specifc model. Re-populate data • Use memory card for using correct memory the specifc model. card if required. • Insert memory card BEFORE turning power ON.
TROUBLESHOOTING Symptoms of Abnormal Diagnostic/ Operation (Legacy Status LED Fault Description & ComfortNet™ Codes Thermostat) • Furnace fails to operate. • Integrated control module LED display provides b4 error code. • ComfortNet™ thermostat “Call for Service” icon illuminated. • ComfortNet™ thermostat scrolls “Check Furnace” message. b4 • Furnace fails to operate. • Integrated control module LED display provides b5 error code. • ComfortNet™ thermostat “Call for Service” icon illuminated.
TROUBLESHOOTING INTERNAL CONTROL FAULT/NO POWER O E E E n NORMAL OPERATION 0 1 2 LOCKOUT DUE TO EXCESSIVE RETRIES LOW STAGE PRESSURE SWITCH STUCK OPEN E 3 E 4 OPEN HIGH LIMIT SWITCH E 5 E 6 OPEN FUSE E 7 E 8 IGNITER FAULT OR IMPROPER GROUNDING E 9 E A HIGH STAGE PRESSURE SWITCH STUCK OPEN E F d 0 d 4 AUXILIARY SWITCH OPEN b b b b 0 1 2 FLAME DETECTED WHEN NO FLAME SHOULD BE PRESENT LOW FLAME SIGNAL HIGH STAGE PRESSURE SWITCH STUCK CLOSED AT START OF HEATING CYCLE REVERSED 115 VAC POLAR
SYSTEM OPERATION ComfortNet™ System OVERVIEW The ComfortNet system is a system that includes a ComfortNet compatible furnace and air conditioner or heat pump with a CTK0*** thermostat. A valid ComfortNet system could also be a compatible furnace, CTK0*** thermostat and non-communicating, single stage air conditioner. Any other system configurations are considered invalid ComfortNet systems and must be connected as a traditional (or legacy) system (see Electrical Connections for wiring connections).
ComfortNet™ System SYSTEM OPERATION NOTE: Use of an accessory transformer is recommended if installing a dual fuel system. Failure to use the transformer in the outdoor unit could result in overloading of the furnace transformer. 1 2 R When using a CTK03A*or CTK04 thermostat, the included transformer must be used. If your communicating thermostat kit does not include a transformer, an accessory kit is available separately by ordering part TFK01.
SYSTEM OPERATION ComfortNet™ System FURNACE ADVANCED FEATURES MENUS CONFIGURATION Submenu Item Indication (for Display Only; not User Modifiable) Number of Heat Stages (HT STG) Displays the number of furnace heating stages Input Rate (BTU/HR) Displays the furnace input rate in kBtu/hr Motor HP (1/2, ¾, or 1 MTR HP) Displays the furnace indoor blower motor horsepower DIAGNOSTICS Submenu Item Indication/User Modifiable Options Comments Fault 1 (FAULT #1) Most recent furnace fault For display on
SYSTEM OPERATION ComfortNet™ System NON-COMM (APPLIES ONLY TO A COMMUNICATING COMPATIBLE FURNACE MATCHED WITH A NON-COMMUNICATING COMPATIBLE SINGLE STAGE AIR CONDITIONER) Submenu Item User Modifiable Options Cool Airflow (CL CFM) 18, 24, 30, 36, 42, 48, or 60, default is 18 Selects the airflow for the non-CT compatible single stage AC unit Cool Airflow Trim (CL TRM) -10% to +10% in 2% increments, default is 0% Cool Airflow Profile (CL PRFL) A, B, C, or D, default is A Cool ON Delay (CL ON) 5, 10
ComfortNet™ System SYSTEM OPERATION SYSTEM TROUBLESHOOTING NOTE: Refer to the instructions accompanying the ComfortNet compatible outdoor AC/HP unit for troubleshooting information. Refer to the Troubleshooting Chart for a listing of possible furnace error codes, possible causes and corrective actions.
SYSTEM OPERATION TROUBLESHOOTING ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS NOTE: Discharge body’s static electricity before touching unit. An electrostatic discharge can adversely affect electrical components. Use the following precautions during furnace installation and servicing to protect the integrated control module from damage.
SERVICING Some of the electronic boards being used today, with flame rectification, will not function properly and/or at all without polarization of incoming power. Some also require phasing between the primary and secondary sides of step-down transformers. INCOMING POWER METER READS METER READS 120 VOLTS 0 VOLTS VOLT / OHM METER VOLT / OHM METER GND GND THIS IS THE COMMON OR NEUTRAL LEG THIS IS L1 OR THE HOT POWER LEG These then should be wired to the furnace accordingly.
SERVICING 1 1 CUBIC FEET One GAS RATE -- CUBIC FEET PER HOUR 58 Size of Test Dial Size of Test Dial 5 cu/ft Seconds for One Revolution 1/4 cu/ft 1/2 cu/ft 1 cu/ft 2 cu/ft 5 cu/ft 720 1800 36 25 50 100 200 500 327 655 1636 37 -- -- 97 195 486 300 600 1500 38 23 47 95 189 474 277 555 1385 39 -- -- 92 185 462 Seconds for One Revolution 1/4 cu/ft 1/2 cu/ft 1 cu/ft 2 cu/ft 10 90 180 360 11 82 164 12 75 150 13 69 138 14 64 129 257 514 1286
SERVICING Power Failure Blown Fuse Loose Connection Shorted or Broken Wires No Low Voltage Faulty Thermostat Faulty Transformer Poor or High Resistance Ground Faulty Ignition Control Gas Valve or Gas Supply Shut Off Faulty Induced Draft Blower Faulty Blower Motor (ECM) Broken or Shorted Ignitor Dirty Flame Sensor, Low UA Stuck Gas Valve Faulty Gas Valve Open Auxiliary Limit Improper Air Flow or Distribution Cycling on Limit Delayed Ignition • • • • • • • • • • • • • • • • • • • • • Furnace Undersized F
SERVICING SERVICE NUMBERS S-1 CHECKING VOLTAGE ....................... 61 S-305 CHECKING MAIN BURNERS ............. 69 S-2 CHECKING WIRING .......................... 61 S-306 CHECKING ORIFICES ....................... 69 CHECKING THERMOSTAT, WIRING S-307 CHECKING GAS PRESSURE ........... 69 AND ANTICIPATOR ............................ 61 S-308 CHECKING HOT SURFACE IGNITOR .................. 71 S-3A THERMOSTAT AND WIRING ............. 61 S-3B HEATING ANTICIPATOR ....................
SERVICING S-1 CHECKING VOLTAGE CHECKING THERMOSTAT, WIRING AND ANTICIPATOR WARNING HIGH VOLTAGE DISCONNECT ALL POWER BEFORE SERVICING OR CHANGING ANY ELECTRICAL WIRING. MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO DO SO MAY CAUSE S-3A THERMOSTAT AND WIRING WARNING DISCONNECT ALL POWER BEFORE SERVICING. PROPERTY DAMAGE, PERSONAL INJURY OR DEATH. 1. Remove the burner door. 2. Remove cover from the Junction Box and gain access to incoming power lines. With Power ON: WARNING 1.
SERVICING S-4 CHECKING TRANSFORMER AND Control CIRCUIT A step-down transformer 120 volt primary to 24 volt secondary, 40 VA (Heating and Cooling Models) supplies ample capacity of power for either operation. WARNING HIGH VOLTAGE DISCONNECT ALL POWER BEFORE SERVICING OR CHANGING ANY ELECTRICAL WIRING. MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO DO SO MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH. ECM Control Connections ECM control connections are made through the integrated ignition control.
SERVICING 6. Ensure motor and wheel turn freely. Check for interference between wheel and housing or wheel and motor. Repair or replace as needed. 7. Check housing for cracks and/or corrosion. Repair or replace as needed. 8. Check motor mounting bracket. Ensure mouting bracket is tightly secured to the housing. Ensure bracket is not cracked or broken. Replace or repair as needed.
SERVICING Motor Control/End Bell Checks 5 AC Line Hot Connection 4 AC Line Neutral Connection 3 Gnd 2 } 1 Lines 1 and 2 will be connected for 120VAC Power Connector applications only POWER CONNECTOR (1/2 HP MOTORS) "Motor Half“ (Viewed from Plug End) inductor AC Line Hot Connection 5 HIGH VOLTAGE! Disconnect ALL power before servicing or installing. Multiple power sources may be present. Failure to do so may cause property damage, personal injury or death. 1. Disconnect power to the furnace.
SERVICING Too great of an external static pressure will result in insufficient air that can cause excessive temperature rise, resulting in limit tripping, etc. Whereas not enough static may result in motor overloading. To determine proper air movement, proceed as follows: 1. With clean filters in the furnace, use a draft gauge (inclined manometer) to measure the static pressure of the return duct at the inlet of the furnace. (Negative Pressure) 7. Locate the 3-circuit connector in the control/end bell.
SERVICING PRIMARY LIMIT CONTROL may result in condensing in or overheating of the heat exchanger. An airflow and temperature rise table is provided in the blower performance specification section. Determine and adjust temperature rise as follows: 1. Operate furnace with burners firing for approximately ten minutes. Check BTU input to furnace - do not exceed input rating stamped on rating plate. Ensure all registers are open and all duct dampers are in their final (fully or partially open) position.
SERVICING Manual or Automatic Reset Auxiliary Limits Located in Blower Side WARNING HIGH VOLTAGE DISCONNECT ALL POWER BEFORE SERVICING OR INSTALLING THIS UNIT. MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO DO SO MAY CAUSE PROPERTY VOLT / OHM METER DAMAGE, PERSONAL INJURY OR DEATH. 1. Remove the wires from the auxiliary limit control terminals. COLOR IDENTIFYING TAB 2. Using an ohmmeter, test for continuity across the two terminals (only test when the auxiliary limit is at room temperature).
SERVICING FLAME ROLLOUT SWITCHES * * * * 2 * * * Flame Rollout Switch Location (90% Upflow Furnace Shown, Counterflow Similar) 1. Remove burner compartment door to gain access to the induced draft blower motor. 2. Disconnect the motor wire leads from its connection point at the induced draft motor. 3. Using a ohmmeter, test for continuity between each of the motor leads. 4. Touch one probe of the ohmmeter to the motor frame (ground) and the other probe in turn to each lead.
SERVICING S-305 CHECKING MAIN BURNERS The main burners are used to provide complete combustion of various fuels in a limited space, and transfer this heat of the burning process to the heat exchanger. Proper ignition, combustion, and extinction are primarily due to burner design, orifice sizing, gas pressure, primary and secondary air, vent and proper seating of burners. Orifices should be treated with care in order to prevent damage.
SERVICING WARNING DISCONNECT ELECTRICAL POWER WARNING AND SHUT OFF GAS SUPPLY. 1. After turning off gas to furnace at the manual gas shutoff valve external to the furnace, remove burner compartment door to gain access to the gas valve. 2. Connect a calibrated water manometer (or appropriate gas pressure gauge) at either the gas valve inlet pressure tap or the gas piping drip leg as shown in the following figures.
SERVICING WARNING WARNING HIGH VOLTAGE DISCONNECT ALL ELECTRICAL POWER LINE VOLTAGE NOW PRESENT 3. Turn ON the gas and electrical power supply and operate the furnace. 4. White-Rodgers 36J54 Valves: a. Back outlet pressure test screw (inlet/outlet pressure boss) out one turn (counterclockwise, not more than one turn). AND SHUT OFF GAS SUPPLY BEFORE SERVICING OR INSTALLING. Manifold Gas Pressure Gas Natural Gas Rate High Stage Low Stage Range 3.2 to 3.8" w.c. 1.6 to 2.2" w.c. Nominal 3.5" w.c. 1.
SERVICING 5. Reconnect ignitor. WARNING LINE VOLTAGE NOW PRESENT 6. Place unit in heating cycle, measure current draw of ignitor during preheat cycle. The steady state current at 120V is 0.37 to 0.68 amps. 7. After checking and/or replacing of hot surface ignitor, reinstall burner compartment door and verify proper unit operation. 3. Remove the pressure control hose from the control and interconnect with an inclined manometer as shown in the following figure. 4.
SERVICING In some areas the gas supplier may artificially derate the gas in an effort to compensate for the effects of altitude. If the gas is artificially derated the appropriate orfice size must be determined based on the BTU/ft3 content of the derated gas and the altitude. Refer to the National Fuel Gas Code, NFPA 54/ANSI Z223.1, and information provided by the gas supplier to determine the proper orifice size.
SERVICING b. The two-stage variable speed furnaces should have 120 Volts at the motor at all times, even without a call for cooling or heating. These motors receive their operational signals through the 4-pin wiring harness, connected between the motor and integrated control board. NOTE: For complete troubleshooting information on units using the ECM blower motors, refer to the servicing section - Checking Air Circulator Blowers (S-16B) in this service manual.
SERVICING 3. Insert the memory card in the slot on the control board. WARNING HIGH VOLTAGE DISCONNECT ALL POWER BEFORE SERVICING OR INSTALLING THIS UNIT. MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO DO SO MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH. 1. Disconnect the flame sensor wire from the sensor. 2. Connect a micro-amp meter in series with this wire and the sensor terminal. 3.
MAINTENANCE WARNING HIGH VOLTAGE DISCONNECT ALL POWER BEFORE SERVICING OR INSTALLING THIS UNIT. MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO DO SO MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH. CAUTION IF YOU MUST HANDLE THE ITNITOR, HANDLE WITH CARE. T OUCHING THE IG NITOR BODY WITH BARE FINGERS, ROUG H HANDLING, OR VIBRATIO N COULD RESULT IN EARLY IGNITO R FAILURE. O NLY A Q UALIFIED SERVICER SHOULD EVER HANDLE THE IGNITO R.
MAINTENANCE CONDENSATE DRAINAGE SYSTEM (QUALIFIED SERVICER ONLY) The drain tubes, trap, and field supplied drain line must be checked annually and cleaned as often as necessary to ensure proper condensate drainage. To conduct a heating performance test, the BTU input to the furnace must be calculated. FLAME SENSOR (QUALIFIED SERVICER ONLY) To find the BTU input, multiply the number of cubic feet of gas consumed per hour by the heating value of the gas being used.
ACCESSORY WIRING DIAGRAMS HIGH VOLTAGE! DISCONNECT ALL POWER BEFORE SERVICING OR INSTALLING THIS UNIT. MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO DO SO MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
ACCESSORY WIRING DIAGRAMS HIGH VOLTAGE! DISCONNECT ALL POWER BEFORE SERVICING OR INSTALLING THIS UNIT. MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO DO SO MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH. INTEGRATED IGNITION CONTROL 1 2 R C G W1 W2 Y1 Y2 O DE HUM WHITE BLACK GREEN 70 80 60 50 40 ON 30 DE-HUMIDISTAT DE-HUMIDISTAT - DEHUM1 This wiring diagram is for reference only. Not all wiring is as shown above. Refer to the appropriate wiring diagram for the unit being serviced.