Goodman GM9S96 error code EAF
Flame signal out of range during a heat cycle
Quick answer
On Goodman GM9S96 (2020s), EAF is a fault. It means flame signal out of range during a heat cycle. A first thing to check: Flame sensor dirty, corroded, or at the wrong distance from the flame.
- Applies to
- Goodman GM9S96
- Goodman GM9S96 and GR9S96 alphanumeric codes · Furnace · 2020s
- Type of code
- Fault
- Urgency: Stop using it
- First safe check
- Look at the flame itself. Steady and roughly vertical, blue, and lifting evenly off the port is what you want.
What EAF means on this model
During a heat call the flame signal the control received was outside the range it considers valid. The burner was running, but the sensor was not reading a stable flame. The control shut the burners down rather than keep an unstable flame going, because an unstable flame burns incompletely.
Symptoms you will notice
- Furnace starts then stops after a short run
- Burner lights but the furnace will not stay on
- Furnace may restart on its own
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:
- Flame sensor dirty, corroded, or at the wrong distance from the flame
- Poor ground at the burner box
- Damaged sensor wiring
- Dirty burner ports or a misaligned burner assembly
- Gas pressure problem producing an unsteady flame
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.
- Look at the flame itself. Steady and roughly vertical, blue, and lifting evenly off the port is what you want.
- Clean the flame sensor rod with fine steel wool and confirm the ground screw is tight on bare metal.
- Look at the burner ports for obvious blockage.
Do not do these
- ×Do not adjust gas pressure or orifices.
- ×Do not bypass the flame sensor.
- ×Do not run the furnace if the flame is yellow or orange rather than blue.
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.
Sensor cleaning is fine. Gas pressure work is not.
What it costs to fix
Parts
Flame sensor $20 to $60. Orifice kit $20 to $60. Gas valve $150 to $400.
Labor
One to two hours.
DIY or technician
Sensor cleaning is fine. Gas pressure work is not.
Typical US part and labor ranges, 2026. They vary by region, model and contractor, so treat them as a planning figure, not a quote.
Scope of this code
- Code table
- Goodman GM9S96 and GR9S96 alphanumeric codes
- Models in scope
- Goodman GM9S96, 2020s
- Checked
- Confirm on your own unit
- Find the model number on the data plate, then check this code in the service manual for that model. Manufacturers revise code tables between model years, and a revised board can renumber a fault.