5 flashesGoodman, Amana, Daikin · GMV / GMH / GMS / GMN · Furnace

Goodman, Amana, Daikin GMV / GMH / GMS / GMN error code 5 flashes

Flame detected when no flame should be present

Goodman is the platform name, and your unit may not say it

Amana AMV / GCH / GDS, Daikin GMV / GMH / GMS / GMN platform are the same board with a different badge, so this page covers all of them. The fault, the checks and the parts are identical, which is why there is one page rather than one per brand.

Stop using it

Also written as 5 blinks

Which models this applies to. Applies to every legacy flash furnace in this group: GMV8 / GMV9, GCH / GDH / GME / GMH, GDS / GHS / GMS / GKS, and GMN / GMP / GMT.

Quick answer

On Goodman GMV / GMH / GMS / GMN (1990s-2000s), 5 flashes is a fault. It means flame detected when no flame should be present. A first thing to check: Leaking gas valve seat, which is a gas leak and needs immediate attention.

Applies to: Goodman GMV / GMH / GMS / GMN; Goodman, Amana and Daikin legacy furnace flash codes (GMV, GMH, GMS, GMN series) · Furnace · 1990s-2000s
Type of code: Fault; Urgency: Stop using it
First safe check: Do not go looking for a gas smell with a lighter or a flashlight. If you smell gas, leave and call the gas utility from outside.

Checked 2026-09-26

What 5 flashes means on this model

The control detected a flame when the gas valve was closed and no burner was supposed to be lit. It shuts down immediately. Either something is leaking fuel into the burner area, or the flame sensor is seeing light or heat from somewhere it should not.

Symptoms you will notice

Furnace will not fire
You can hear or smell gas near the furnace
Code appears right after the unit starts
Blower runs but no heat

Common causes

The code tells you what the control detected, not which part failed. These are the causes we see most often, roughly in order of likelihood:

Leaking gas valve seat, which is a gas leak and needs immediate attention
Failed or improperly grounded flame sensor
Pilot light left on somewhere in the burner compartment
Light or heat from a nearby source reaching the flame sensor
Cracked heat exchanger allowing combustion to reach the flame sensor area

What you can safely check

These are homeowner-level checks. None of them need you to open a live electrical compartment or work on gas.

Do not go looking for a gas smell with a lighter or a flashlight. If you smell gas, leave and call the gas utility from outside.
Look at the flame sensor. It is a thin rod near the burner. It should be clean and correctly grounded to the burner box.
Confirm nothing else in the burner compartment is lit, such as a pilot that was left on.

Do not do these

×Do not operate the furnace if you smell gas. Leave the property and call the gas utility or 911 from outside.
×Do not bridge the flame sensor.
×Do not light anything inside the burner compartment.

When to call a technician

Stop using the appliance and call today

This one is a safety limit, not a nuisance. The control is shutting the unit down to prevent damage or a hazard, and it will keep doing that until the underlying cause is fixed. Running it anyway risks the expensive failure it was designed to prevent.

This is a fuel-burning appliance, so treat anything involving a burner, gas valve or flue as technician work. If you smell gas at any point, leave the property and call the gas utility from outside rather than continuing to diagnose.
If the appliance has stopped mid-cycle, is making a noise you have not heard before, or smells burnt, stop reading here and call. Those are symptoms of something the fault code does not describe well enough.

Do not DIY a suspected gas leak. This one goes to a licensed technician the moment you smell it.

What it costs to fix

Parts

Flame sensor $20 to $60. Gas valve $150 to $400. Ignition control board $150 to $350.

Labor

One to two hours for a sensor. A leaking gas valve is same-day work, not a next-week appointment.

DIY or technician