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Goodman gas furnace red light flashing rapidly: Electrical fault or configuration error
Gas furnace, Canada and United States
This code means one of two things, depending on your model. Find your model family below, then read the section for it. The model number is on the rating label on the side of the unit.
Find your model family
| If you have | It means |
|---|---|
| GDH8, GDS8, GKS9, GMH8 / AMH8, GMH95 / GCH95 / AMH95, GMS8 / AMS8, GMSS92 / GCSS92 / AMSS92, GMSS96 / GCSS96 / AMSS96 / ACSS96, GMES80 / GCES80 / AMES80 / ACES80, GMES92, GMES96 / GCES96 / AMES96 / ACES96 | Reversed polarity or poor ground |
| GMEC96 / GCEC96 / AMEC96 / ACEC96 | Twinning error |
Reversed polarity or poor ground
On GDH8, GDS8, GKS9, GMH8 / AMH8, GMH95 / GCH95 / AMH95, GMS8 / AMS8, GMSS92 / GCSS92 / AMSS92, GMSS96 / GCSS96 / AMSS96 / ACSS96, GMES80 / GCES80 / AMES80 / ACES80, GMES92, GMES96 / GCES96 / AMES96 / ACES96.
The light flashes continuously because the 115 V or 24 V supply polarity is reversed, the transformer wires are swapped, or the furnace is poorly grounded. The furnace does not run.
This needs a licensed gas technician. There is nothing safe to check yourself. Leave the covers on and book a professional.
What causes it
GMS8, GMH8, GMSS9, GMH95 and GKS9 boards
-
The 115 V supply to the furnace or control board is connected with its polarity reversed.
-
The two wires to the transformer are swapped (red and blue on GMS8, GMH8 and GMH95; orange and gray on GMSS9 and GKS9).
-
A poor unit ground.
GMES80, GMES92 and GMES96 boards
-
The 115 V supply to the furnace or control board is connected with its polarity reversed.
-
The orange and gray wires to the transformer are swapped.
-
A poor unit ground.
How to read this code on your unit
Booking a licensed gas technician
Book a licensed gas technicianlicensed gas technician
- Turn the unit off and leave the covers on. Gas components must only be serviced by a licensed technician.
- Note the code, how often it appears, and the model and serial numbers from the rating label.
- Book a licensed gas technician and give them those details.
Models that show this code
220 models in 11 ranges
| Range | Models |
|---|---|
| GDH8 | GDH80403AN, GDH80403AX, GDH80603AN, GDH80603AX, GDH80804BN, GDH80804BX, GDH81005CN, GDH81005CX |
| GDS8 | GDS80403AN, GDS80403AX, GDS80603AN, GDS80603AX, GDS80804BN, GDS80804BX, GDS81005CN, GDS81005CX |
| GKS9 | GKS90453BX, GKS90703BX, GKS90704CX, GKS90904CX, GKS90905DX, GKS91155DX |
| GMH8 / AMH8 | GMH80403AN, GMH80403AX, GMH80603AN, GMH80603AX, GMH80604BN, GMH80604BX, GMH80803BN, GMH80803BX, GMH80804BN, GMH80804BX, GMH80805CN, GMH80805CX, GMH81005CN, GMH81005CX, GMH81205DN, GMH81205DX, GMH81405DN, AMH80403AN, AMH80403AX, AMH80603AN, AMH80603AX, AMH80604BN, AMH80604BX, AMH80803BN, AMH80803BX, AMH80804BN, AMH80804BX, AMH80805CN, AMH80805CX, AMH81005CN, AMH81005CX, AMH81205DN, AMH81205DX, AMH81405DX |
| GMH95 / GCH95 / AMH95 | GMH950453BX, GMH950703BX, GMH950704CX, GMH950904CX, GMH950905CX, GMH950905DX, GMH951155DX, AMH950453BX, AMH950703BX, AMH950704CX, AMH950904CX, AMH950905CX, AMH950905DX, AMH951155DX, GCH950453BX, GCH950703BX, GCH950704CX, GCH950905DX |
| GMS8 / AMS8 | GMS80403AN, GMS80403AX, GMS80603AN, GMS80603AX, GMS80604BN, GMS80604BX, GMS80804BN, GMS80804BX, GMS80805CN, GMS80805CX, GMS81005CN, GMS81005CX, GMS81205DN, GMS81205DX, GMS81405DN, AMS80403AX, AMS80603AX, AMS80604BX, AMS80804BX, AMS80805CX, AMS81005CX, AMS81205DX, AMS81405DN |
| GMSS92 / GCSS92 / AMSS92 | GMSS920402BN, GMSS920403AN, GMSS920603BN, GMSS920803BN, GMSS920804CN, GMSS920805CN, GMSS921004CN, GMSS921005CN, GMSS921205DN, AMSS920402BN, AMSS920403AN, AMSS920603BN, AMSS920803BN, AMSS920804CN, AMSS920805CN, AMSS921004CN, AMSS921005CN, AMSS921205DN, GCSS920402BN, GCSS920603BN, GCSS920804CN, GCSS921005CN |
| GMSS96 / GCSS96 / AMSS96 / ACSS96 | GMSS960402BN, GMSS960403AN, GMSS960603BN, GMSS960803BN, GMSS960804CN, GMSS960805CN, GMSS961005CN, GMSS961205DN, AMSS960402BN, AMSS960403AN, AMSS960603BN, AMSS960803BN, AMSS960804CN, AMSS960805CN, AMSS961005CN, AMSS961205DN, GCSS960402BN, GCSS960603BN, GCSS960804CN, GCSS961005CN, GCSS961205DN, ACSS960402BN, ACSS960603BN, ACSS960804CN, ACSS961005CN, ACSS961205DN |
| GMES80 / GCES80 / AMES80 / ACES80 | GMES800403AN, GMES800403AX, GMES800603AN, GMES800603AX, GMES800603BN, GMES800603BX, GMES800604BN, GMES800604BX, GMES800803BN, GMES800803BX, GMES800804BN, GMES800804BX, GMES800804CN, GMES800804CX, GMES800805CN, GMES800805CX, GMES801005CN, GMES801005CX, GMES801205DN, AMES800403AX, AMES800603AX, AMES800603BN, AMES800604BX, AMES800803BX, AMES800804BX, AMES800804CX, AMES800805CX, AMES801005CX, AMES801205DX, GCES800403AN, GCES800403AX, GCES800603AN, GCES800603AX, GCES800804BN, GCES800804BX, GCES801005CN, GCES801005CX, ACES800403AN, ACES800403AX, ACES800603AN, ACES800603AX, ACES800804BX, ACES801005CX |
| GMES92 | GMES920403AN, GMES920603BN, GMES920803BN, GMES920804CN, GMES920805CN, GMES921004CN, GMES921005CN, GMES921205DN |
| GMES96 / GCES96 / AMES96 / ACES96 | GMES960403AN, GMES960603BN, GMES960803BN, GMES960804CN, GMES960805CN, GMES961005CN, GMES961205DN, AMES960403AN, AMES960603BN, AMES960803BN, AMES960804CN, AMES960805CN, AMES961005CN, AMES961205DN, GCES960403BN, GCES960603BN, GCES960804CN, GCES961005CN, GCES961205DN, ACES960403BN, ACES960603BN, ACES960804CN, ACES961005CN, ACES961205DN |
Where this comes from
- GMS8/GMH8 gas furnace installation instructions (IO-446F) , page 38, 46
- GMSS92/GMSS96 gas furnace installation instructions (IOG-2009Q) , page 43
- GMH95 gas furnace installation instructions (IO-299R) , page 43
- GKS9 gas furnace installation instructions (IO-300O) , page 36
- GMES80 gas furnace installation instructions (IOG-2021H) , page 26, 31
- GMES92/GMES96 gas furnace installation instructions (IOG-2020J) , page 38, 42
Checked against the manufacturer's manual on 9 October 2026.
Twinning error
On GMEC96 / GCEC96 / AMEC96 / ACEC96.
A rapidly flashing red light means a twinning error between two furnaces wired to work together, and the furnace does not run.
This needs a licensed gas technician. There is nothing safe to check yourself. Leave the covers on and book a professional.
What causes it
-
The twinning wiring between the two furnaces is wrong.
How to read this code on your unit
Booking a licensed gas technician
Book a licensed gas technicianlicensed gas technician
- Turn the unit off and leave the covers on. Gas components must only be serviced by a licensed technician.
- Note the code, how often it appears, and the model and serial numbers from the rating label.
- Book a licensed gas technician and give them those details.
Models that show this code
30 models in 1 range
| Range | Models |
|---|---|
| GMEC96 / GCEC96 / AMEC96 / ACEC96 | GMEC960302BN, GMEC960303AN, GMEC960402BN, GMEC960403AN, GMEC960603AN, GMEC960603BN, GMEC960803BN, GMEC960804CN, GMEC961004CN, GMEC961005CN, GMEC961205DN, AMEC960302BN, AMEC960303AN, AMEC960402BN, AMEC960403AN, AMEC960603AN, AMEC960603BN, AMEC960803BN, AMEC960804CN, AMEC961004CN, AMEC961005CN, AMEC961205DN, GCEC960403BN, GCEC960603BN, GCEC960803BN, GCEC961005CN, ACEC960403BN, ACEC960603BN, ACEC960803BN, ACEC961005CN |
Where this comes from
Checked against the manufacturer's manual on 9 October 2026.
Other Goodman gas furnace codes
| Code | Meaning | What you can do |
|---|---|---|
| d4 | Invalid memory card data | Call a pro |
| E10 | Grounding fault or poor neutral connection | Call a pro |
| EA | Reversed polarity or poor ground | Call a pro |
| Eb2 | Blower motor size does not match the shared data | Call a pro |
| Ed0 | No shared data loaded on the control board | Call a pro |
| Ed1 | Invalid shared data | Call a pro |
| Ed8 | Invalid call, outdoor unit setting does not match | Call a pro |
| EEA | Reversed polarity or poor ground | Call a pro |
| EEH | Twinning error | Call a pro |
| 3 amber flashes | Second-stage heat call without first stage | Safe checks first, then a pro |
| 4 amber flashes | Cooling call without a fan signal | Safe checks first, then a pro |
| 9 red flashes | Configuration error or electrical fault (depends on model) | Call a pro |
See all electrical fault codes on gas furnaces across brands.
See all configuration error codes on gas furnaces across brands.