g43 service manual - Heating and Air Parts

VIII−Ignition Control Board Troubleshooting ChartUPON INITIAL POWER UP, REMOVE ALL THERMOSTAT DEMANDS TO THE UNITPROBLEM: 1 UNIT FAILS TO OPERATE IN THE COOLING, HEATING, OR CONTINUOUS FAN MODECondition Possible Cause Corrective Action / Comments1.1− Both diagnostic lights fail to light up.1.1.1Main voltage 120V not supplied to unit.ACTION 1 − Check 120V main voltage.Determine cause of main power failure.LED#1−OffLED#2−Off1.2− Diagnostic lights flash the roll−outcode.LED#1−On,LED#2−Slow Flash1.31.1.2Miswiring of furnace or improper connections.1.1.3Blown fuse1.1.4Door interlock switch failure.1.1.5Transformer Failure.1.1.6Failed control board.1.2.1Roll−out switch open.1.2.2Roll−out switch failure.1.2.3Miswiring iring or improper connections atroll−out switch.1.2.412 pin connector failure131 1.3.1LED#1−Fast Flash,120V main power polarity reversed.LED#2−Slow Flash.1.4 1.4.1Open combustion air inducer motorcircuit.LED#1−Slow FlashLED#2−Slow Flash1.4.2Failed combustion air inducer motor.ACTION 1 − Check for correct wiring of 120V topower make up box and transformer.ACTION 2 − Check 24V wiring to control board.ACTION 1 − Replace fuse.ACTION 2 − If fuse still blows, check for short.ACTION 1 − Check that door switch is activatedwhen door is closed.ACTION 2 − Check wire connections to switch, replaceloose connectors.ACTION 3 − Check continuity of switch in closedposition. Replace if defective.ACTION 1 − Check that transformer output is24V. Replace if defective.ACTION 1 − If all the above items have beenchecked, replace board.ACTION 1 − Manually reset the roll−out switchby pushing the top button.ACTION 2 − Determine the cause of the roll−outswitch activation before leaving furnace.ACTION 1 − Check continuity across roll−outswitch. Replace roll−out switch if switch is resetbut does not have continuity.ACTION 1 − Check wiring connections to switch.ACTION 1 − Check 12−pin connector for properconnection to control board.ACTION 2 − Check continuity of the multi plugpin.ACTION 1 − Check the 120V has line and neutralcorrectly input into control.ACTION 2 − Reverse the line and neutral at the120V field connection.ACTION 1 − Check for 120V to combustion airinducer. If no power, check wire and connections.ACTION 1 − If power is present at blower, replaceblower.Page 50