Goodman Gas Furnace: GMS8/GMS9 OR GCS8/GCS9 Re: Lockout Codes # of Flashes Description Off No Power or Faulty Control On Normal Operation 1 Ignition lockout (3 failed tries) - 1hr Auto Reset 2 Pressure switch stuck closed 3 Pressure switch stuck...

Goodman Gas Furnace: GMS9/GMD9/GMH9 Re: Code 1 / Won't Ignite Code 1 = 3 Failed Ignition Attempts ► Be aware that the furnace Condensate Pressure Switch breaks power to the gas valve and will cause a Fault Code 1 (Does not cause a Code 3). Qty Possible Causes: Dirty Flame...

Goodman Gas Furnace: GMS9 Re: Flashing Code 3 If, after the vent blower is energized, the pressure switch does not close, the control will keep the blower on and wait for the switch to close. The diagnostic code for this problem is 3 short flashes followed by a pause. ► There are 2...

Goodman Gas Furnace: GMS9/GCS9 Re: Flashing Code 4 (Assuming original control board) Code 4 = Limit Circuit Open If the Limit Circuit opens, the burners will be de-energized and the air circulation and vent blower will be turned on until the Limit Circuit closes. The diagnostic light code...