INTEGRATED FURNACE CONTROL MODULE
Flame Sensor Check
Does main burner remain lit?
Does ignitor remain energized with flame present?
Is blower at heat speed within 1 minute of burner ignition?
System is functioning properly.
De-energize system. Disconnect 12-pin connector. Connect ohmmeter from flame sensor pin FP to burner GROUND.
Is 120V present at control terminals HEAT & CIR NEUTRAL?
Repair wiring and/or replace indoor blower motor. Check operation.
Replace control module. Check operation.
Is resistance less than 50 megohms (50,000,000 Ohms)?
Disconnect flame sensor from wire. Measure continuity from wire end to FP pin on 12-pin connector.
Disconnect AC power to system at main fuse or circuit breaker. Connect voltmeter from control terminal LINE NEUTRAL to BURNER GROUND. Energize module.
Is 120V present at burner ground?
Reverse 120V LINE & NEUTRAL wires. Energize system. Check operation.
Disconnect lead from flame sensor. Connect ohmmeter from sensor to burner ground.
Is sensor lead good?
Is control ground wire connected to burner ground?
Connect a microammeter in series with flame sensor and sensor lead. Energize system. Measure current when burner ignites.
Clean surface of flame sensor with fine steel wool. Reinstall. Check operation.
Repair or replace wire. Energize system. Check operation.
Connect ground wire from burner to 12-pin connector terminal GROUND. Check operation.
Is 1 microamp or more present?
Remove sensor. Does sensor have carbon or dust buildup?
Is resistance less than 50 megohms?
Replace sensor. Energize system. Check operation.
Replace flame sensor lead. Check operation.
Replace control. Check operation.
If diagnostic indicator (LED) shows continuous flashing, turn off gas supply at source before disconnecting electrical power!