ICP G9MAE0601714A Service And Technical Support Manual

Contents

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAESpecifications subject to change without notice.440 04 4700 00 25! WARNINGELECTRICAL SHOCK HAZARDFailure to follow this warning could result in personal injury, ordeath.Blower access door switch opens 115−v power to furnacecontrol. No component operation can occur unless switch isclosed. Exercise caution to avoid electrical shock fromexposed electrical components when manually closing thisswitch for service purposes.16. Downflow or horizontal furnaces with vent pipe throughfurnace only:a. Install and connect short piece of vent pipe insidefurnace to existing vent.b. Connect vent connector to vent elbow.17. Turn on electrical supply. If outdoor temperature is below70F (21C), turn off circuit breaker to outdoor unitbefore running furnace in the cooling cycle. Manuallyclose blower access panel door switch. Use a piece oftape to hold switch closed. Check for proper rotation andspeed changes between heating and cooling byjumpering R to G and R to Y/Y2 on furnace controlthermostat terminals. Turn outdoor circuit breaker onafter completing cooling cycle. (See Figure 3)NOTE: If R−W/W1 thermostat terminals are jumpered at thetime blower access door switch is closed, blower will run for 90seconds before beginning a heating cycle.a. Perform component self−test as shown at the bottom ofthe SERVICE label, located on the front of bloweraccess door.b. Verify blower is rotating in the correct direction18. If furnace is operating properly, RELEASE BLOWERACCESS DOOR SWITCH. Remove any jumpers orreconnect any disconnected thermostat leads. Replaceblower access door.19. Downflow or horizontal furnaces with vent pipe throughfurnace only:a. Install and connect short piece of vent pipe insidefurnace to existing vent.b. Connect vent connector to vent elbow.20. Reinstall outer door.21. Turn on gas supply and cycle furnace through onecomplete heating cycle. Verify the furnace temperaturerise as shown in Adjustments Section. Adjusttemperature rise as shown in Adjustments Section.Cleaning Burners and Flame SensorThe following items must be performed by a qualified servicetechnician. If the burners develop an accumulation of light dirtor dust, they may be cleaned by using the following procedure:NOTE: Use a back-up wrench on the gas valve to prevent thevalve from rotating on the manifold or damaging the mountingto the burner assembly.Refer to Figure 9.1. Disconnect power at external disconnect, fuse or circuitbreaker.2. Turn off gas at external shut-off or gas meter.3. Remove outer doors and set aside.4. Turn electric switch on gas valve to OFF.5. Disconnect the gas pipe from gas valve and remove pipefrom the furnace casing.6. Disconnect the connector harness from gas valve.7. Disconnect Hot Surface Igniter (HSI) wires from HSI.8. Disconnect Flame Sensor wire from Flame Sensor.9. Support the manifold and remove the four (4) screws thatsecure the manifold assembly to the burner assemblyand set aside. Note the location of the green/yellow wireand ground terminal.10. Inspect the orifices in the manifold assembly forblockages or obstructions. Remove orifice and clean orreplace orifice.11. Remove the four (4) screws that attach the top plate ofthe casing to the furnace.12. Raise top plate up slightly and prop it up with a smallpiece of wood or folded cardboard.13. Support the burner assembly and remove the screwsthat attach the burner assembly to the heat exchangercell panel.14. Remove wires from both rollout switches.15. Slide one-piece burner assembly out of slots on sides ofburner assembly.16. Remove the flame sensor from the burner assembly.17. (Optional) Remove the Hot Surface Igniter (HSI) andbracket from the burner assembly.18. Check igniter resistance. Nominal resistance is 40 to 70ohms at room temperature and is stable over the life ofthe igniter.19. Clean burner assembly with a brush and a vacuum.20. Clean the flame sensor with fine steel wool (0000 grade).Do not use sand paper or emery cloth.To reinstall burner assembly:1. Install the Hot Surface Igniter (HSI) and bracket in burnerassembly.2. Install flame sensor on burner assembly.3. Align the edges of the one-piece burner assembly withthe slots in the burner assembly and slide the burnersforward until they are fully seated in the burnerassembly.4. Align the orifices in the manifold assembly with thesupport rings on the end of the burner.5. Insert the orifices in the support rings of the burners.NOTE: If manifold does not fit flush against the burnerassembly, do not force the manifold on the burner assembly.The burners are not fully seated forward in the burnerassembly. Remove the manifold and check burner positioningin the burner assembly before re-installing the manifold.6. Attach the green/yellow wire and ground terminal to oneof the manifold mounting screws.7. Install the remaining manifold mounting screws.8. Check the igniter alignment. See Figure 9, Figure 10and Figure 11.