How do you fix Goodman flashes?

If you smell gas: leave the building, operate no electrical switches, and call your gas utility's emergency line or the fire service from outside. With no gas smell, switch the furnace off at its service switch and leave it off until a licensed technician has seen it. Full steps and safety notes are on this page.

Goodman furnace 10 red flashes: Gas flow detected with a call for heat

Ten red flashes means the control has detected gas flow at a point in the heating sequence where it did not command it. This is a gas valve fault and needs a technician.

This code is not a homeowner repair. Faults in this group involve the gas valve, the burner compartment, or the heat exchanger — the parts whose failure can put combustion products, including carbon monoxide, into the air the house breathes. Do not reset it repeatedly to keep the heat on. Have it looked at by a licensed technician, and make sure there is a working carbon monoxide alarm on every level of the home, including the level the furnace is on. The conditions that mean stop now.

Applies to: Goodman GMEC96 and Amana AMEC96 two-stage gas furnaces with a three-colour diagnostic LED.

What it means

This code sits in the same family as the flame-detected-with-valve-closed fault, but it is specifically about gas flow during a call for heat rather than at rest. The control tracks what it has commanded the gas valve to do and compares that against what it observes. A mismatch means the valve is not behaving as instructed — most likely passing gas when it should not be, or opening at the wrong point in the sequence. Because the gas valve is the component that admits fuel, a control that cannot predict its behaviour cannot operate the furnace safely, so it stops.

Most common causes

A gas valve passing gas when it should be closed.
A gas valve opening at the wrong point in the sequence.
A miswired gas valve, most often after recent service.
A failed valve relay on the control board.
Wiring damage in the gas valve circuit.
A control board fault misreading the valve state.

How to diagnose it

Note any smell of gas. If there is one, act on the fix below immediately rather than continuing to diagnose.
Do not open the burner compartment while the furnace is powered.
Establish whether the furnace has been serviced recently, since a miswired valve does not develop on its own.
Note whether the inducer runs continuously, which some controls do to purge the heat exchanger.

How to fix it

If you smell gas: leave the building, operate no electrical switches, and call your gas utility's emergency line or the fire service from outside.
With no gas smell, switch the furnace off at its service switch and leave it off until a licensed technician has seen it.
This is entirely technician work, involving the gas valve circuit.
Do not reset repeatedly. If the valve is passing gas, each reset is another opportunity for it to accumulate.

Notes

Goodman's service bulletin SF-042 covers gas valve diagnostics on two stage and communicating furnaces, including how the valve terminals are energised. It is worth a technician consulting it rather than working from general practice, since two-stage valve behaviour differs between model families.

All codes for this manufacturer

Goodman and Amana furnace fault codes — every code, with what differs between models.

Not sure this is your brand?

The same count means something else on other furnaces. What 10 flashes means on every brand puts them side by side.

Models this code appears on

From the manufacturer's per-model database. If your model is not listed, this code may not exist on your board, or it may mean something different — check the model page.

Goodman GMEC96 and Amana AMEC96

The same fault on other control families

Gas flow the control did not command is closely related to, but distinct from, flame out of sequence: one red flash on this board reports unexpected flame, while ten reports unexpected gas — the fault caught one step earlier. York's ten red flashes describes the same event as the gas valve energised with no call for heat, one more near-identical row in the shared table. The flame sensor code hub covers the whole family of flame-and-gas-out-of-sequence codes and where the valve-leak variants fit within it.

What the fix costs

This is gas valve territory, and the repair cost guide prices valve replacement at $300–900 with an unambiguous note attached: never a DIY part. The range is wide because valve access, brand, and staging vary, but there is no cheap branch to hope for here the way there is with sensing faults — a control that detects actual gas flow it did not order is describing hardware letting gas past when it should not. The $75–150 diagnostic confirms it, and on this code that confirmation should happen promptly rather than at the next convenient appointment.

DIY or call a pro?

No homeowner branch exists on this code, and the conservative move goes one step further than just not touching it: if the furnace shows ten red flashes, leave it off. If you can hear burners or smell gas with no call for heat, close the appliance's gas shutoff valve — the lever on the gas line at the furnace — and treat the call as urgent. A valve passing gas without a command is precisely the failure the rest of the furnace's safety system exists to contain, and it is the clearest call-a-professional-today code on this board. Resetting the control does not close a leaking valve; it only clears the report of it.

What this looks like

From the outside, this usually shows up as the furnace turns over but never lights — that walkthrough covers what to check in order, and when it stops being a homeowner job.

Sources

This site is a reference, not a substitute for a licensed HVAC technician. Gas appliances can leak carbon monoxide and cause fire. Anything involving gas lines, the heat exchanger, or the flame sensing circuit should be handled by a licensed professional. Pages are written with AI assistance from the sources listed on each page and checked against them before publishing.