Goodman furnace — Goodman GMVC-series two-stage variable-speed gas furnaces documented in the installation and operating instructions Error Codes Directory
Complete diagnostic reference for Goodman furnace — Goodman GMVC-series two-stage variable-speed gas furnaces documented in the installation and operating instructions fault codes. Each code includes official root causes, safety precautions, and affected replacement components.
Goodman two flashes: the pressure switch is closed when it should be open
Two flashes on a Goodman integrated control reports the pressure switch circuit closed at a point in the sequence where the control expects it open. The control checks the switch before the inducer runs, and a circuit already made at that moment means the switch cannot prove anything about draft once the inducer starts. Applies to: Goodman GMVC-series two-stage variable-speed gas furnaces documented in the installation and operating instructions Take this from the diagnostic table printed in the Goodman GMVC-series installation and operating instructions. Goodman has used other flash counts on earlier and later control platforms, and Amana equipment built on related controls publishes its own table. Take the count from the label inside your own furnace door. Owner-safe checks: Read the flash count through the door sight glass rather than removing the blower door, since opening it can cut control power and clear the code. | Confirm the thermostat is set to heat, is calling, and has good batteries if it uses them. | Look for standing water or staining around the base of the furnace and note anything you find without touching tubing or switches. Qualified technician: Testing a pressure switch, clearing condensate tubing, and inspecting the inducer and vent path are licensed gas-furnace tasks. | Never bridge, jumper, or bypass a pressure switch to make a furnace run. The switch is the only thing confirming that combustion products are leaving the building.
Goodman five flashes: flame sensed when no flame should exist
Five flashes on a Goodman integrated control reports flame sensed when there was no call for heat and the gas valve should have been closed. The control is describing gas burning outside the sequence it commanded, which is why the response is to shut down and involve a licensed engineer rather than to reset and observe. Applies to: Goodman GMVC-series two-stage variable-speed gas furnaces documented in the installation and operating instructions What follows is scoped to GMVC-series equipment and the flash table Goodman prints for it. Other Goodman control generations, and related brands built on similar boards, assign this count differently, so the diagnostic label fixed inside your own furnace door is the authority rather than any chart found elsewhere. Owner-safe checks: Check for any smell of gas indoors, and if one is present leave the property and use the emergency number your gas supplier publishes before doing anything else. | Switch the furnace off at its dedicated service switch so the control stops attempting cycles. | Note whether you actually saw or heard burner activity, or whether only the code was present, and record the time. Qualified technician: A gas valve that does not seat, a burner alight outside its commanded sequence, and flame sensing circuit faults are licensed gas engineering work without exception. | Do not operate, reset, or test the furnace to see whether the code returns. The condition being reported is combustion the control did not ask for.