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Goodman gas furnace code On: Normal operation
Gas furnace, Canada and United States
On means normal operation. The control board has power and is not reporting a fault.
You can often clear this yourself. Work through the causes below in order, most likely first.
What causes it
-
This is normal. If the house is still not heating properly, work through the owner checks for the thermostat, power, filter and grilles before calling for service.
Check the thermostat and the power to the furnaceYou can do this
- Check the thermostat is working and set to HEAT above the room temperature, or to COOL below it if the problem is with cooling.
- If the blower runs all the time, look at the thermostat's fan switch. ON runs the blower constantly; AUTO runs it only while heating or cooling.
- Check that the power switch for the furnace, often a switch on or near it, is turned on.
- Check the electrical panel for a tripped circuit breaker or a failed fuse for the furnace. Reset the breaker or replace the fuse. If the breaker trips again, leave it off and call a qualified servicer.
- Make sure both furnace doors are in place. A switch stops the furnace from running while the blower door is off.
Check and replace the furnace air filterYou can do this
- Turn off the electrical power to the furnace before you take the filter out. Never run the furnace without a filter in place.
- Find the filter. It sits outside the furnace cabinet, in a return air grille, a filter rack on the side of the furnace, or the duct next to it. If you cannot find or reach it, ask your installer.
- Replace a dirty disposable filter with one of the same size that meets UL900 or CAN/ULC-S111. Wash and dry a permanent filter the way its maker describes.
- Fit the filter so the air flows through it in the same direction as before, then turn the power back on.
- Check the filter at least once a month and clean or replace it when it is dirty. A dirty filter is the most common cause of a furnace not working properly.
Clear blocked supply and return grillesYou can do this
- Go round the house and look at every supply register and return air grille.
- Move furniture, curtains, clothes, rugs or anything else that covers or blocks them.
How to read this code on your unit
The code shows on the two-character display on the furnace control board, which you can see through the sight glass on the blower compartment. On means normal operation. A blank display means the board has no power or has failed. A ComfortNet thermostat, if fitted, shows the same codes with a short message and uses EE for an internal fault.
Models that show this code
66 models in 4 ranges
| Range | Models |
|---|---|
| GMVC8 / GCVC8 / AMVC8 / ACVC8 | GMVC80603BN, GMVC80603BX, GMVC80604BN, GMVC80604BX, GMVC80803BN, GMVC80803BX, GMVC80804CN, GMVC80804CX, GMVC80805CN, GMVC80805CX, GMVC80805DN, GMVC80805DX, GMVC81005CN, GMVC81005CX, AMVC80603BN, AMVC80603BX, AMVC80604BN, AMVC80604BX, AMVC80803BN, AMVC80803BX, AMVC80804CN, AMVC80804CX, AMVC80805CN, AMVC80805CX, AMVC80805DN, AMVC80805DX, AMVC81005CN, AMVC81005CX |
| GMVC96 / GCVC96 / AMVC96 / ACVC96 | GMVC960403BN, GMVC960603BN, GMVC960803BN, GMVC960804CN, GMVC961005CN, GMVC961005DN, GMVC961205DN, GCVC960403BN, GCVC960603BN, GCVC960804CN, GCVC961005CN, GCVC961205DN, AMVC960403BN, AMVC960603BN, AMVC960803BN, AMVC960804CN, AMVC961005CN, AMVC961005DN, AMVC961205DN, ACVC960403BN, ACVC960603BN, ACVC960804CN, ACVC961005CN, ACVC961205DN |
| GMVM96 / GCVM96 / AMVM96 / ACVM96 | GMVM960603BX, GMVM960805CX, GMVM961005DX, GMVM961155DX |
| GMVM97 / GCVM97 / AMVM97 / ACVM97 | GMVM970603BN, GMVM970803BN, GMVM970804CN, GMVM971005CN, GMVM971205DN, AMVM970603BN, AMVM970803BN, AMVM970804CN, AMVM971005CN, AMVM971205DN |
Where this comes from
- GMVC96/GCVC96 (revision AA) ComfortNet gas furnace installation instructions (IOG-2008H) , page 51, 52
- GMVC8/GCVC8 ComfortNet gas furnace installation instructions (IOG-2012C) , page 41
- Gas furnace user's information manual (HI-131) , page 8
- Gas furnace user's information manual (HI-124B) , page 8
- GMVM97/GCVM97 (revision AA) modulating gas furnace installation instructions (IOG-2007H) , page 53, 58
- GMVM96/GCVM96 modulating gas furnace installation instructions (IO-406E) , page 52
Checked against the manufacturer's manual on 13 October 2026.
Other Goodman gas furnace codes
| Code | Meaning | What you can do |
|---|---|---|
| IdL | Idle, normal operation | You can often fix it |
| 1 amber flash | Low-stage heat call | You can often fix it |
| 2 amber flashes | High-stage or single-stage heat call | You can often fix it |
| 1 green flash | Low-stage cooling call | You can often fix it |
| 2 green flashes | High-stage or single-stage cooling call | You can often fix it |
| green light flashing rapidly | Fan-only call | You can often fix it |
| steady green light | Standby, waiting for a call | You can often fix it |
| 10 red flashes | Power supply problem or gas valve fault (depends on model) | Depends on your model |
| 11 red flashes | Ignition failure or overheat (depends on model) | Call a pro |
| 12 red flashes | Flue or venting fault / ignition failure (depends on model) | Call a pro |
| red light flashing rapidly | Electrical fault or configuration error (depends on model) | Call a pro |
| steady red light | Normal operation or control board internal fault (depends on model) | Depends on your model |
See all normal operation codes on gas furnaces across brands.