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Goodman gas furnace code EEH: Twinning error
Gas furnace, Canada and United States
The twinning feature between two furnaces is not working.
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 two furnaces are not on the same 115 V supply from the breaker panel.
-
A low-voltage wiring error or loose connections between the furnaces.
-
A faulty control board on one of the furnaces.
How to read this code on your unit
The code shows on the three-character display on the furnace control board, which you can see through the sight glass on the blower compartment. IdL means the furnace is idle and normal. A blank display means the board has no power or has failed.
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
169 models in 10 ranges
| Range | Models |
|---|---|
| GM9C80 / GC9C80 / AM9C80 | GM9C800403AN, GM9C800403AX, GM9C800603AN, GM9C800603AX, GM9C800603BN, GM9C800603BX, GM9C800803BN, GM9C800803BX, GM9C800804BN, GM9C800804BX, GM9C800804CN, GM9C800804CX, GM9C800805CN, GM9C800805CX, GM9C800805DX, GM9C801004CN, GM9C801005CN, GM9C801005CX, GM9C801205DN |
| GM9C96 / GC9C96 / AM9C96 | GM9C960303AN, GM9C960403AN, GM9C960603AN, GM9C960603BN, GM9C960803BN, GM9C960804CN, GM9C961004CN, GM9C961005CN, GM9C961205DN, GC9C960403BN, GC9C960603BN, GC9C960803BN, GC9C961005CN |
| GM9S80 / GC9S80 / AM9S80 / AC9S80 | GM9S800403AN, GM9S800403AX, GM9S800603AN, GM9S800603AX, GM9S800603BN, GM9S800603BX, GM9S800604BN, GM9S800604BX, GM9S800803BN, GM9S800803BX, GM9S800804BN, GM9S800804BX, GM9S800804CN, GM9S800804CX, GM9S800805CN, GM9S800805CX, GM9S801005CN, GM9S801005CX, GM9S801205DN, AM9S800403AX, AM9S800603AX, AM9S800603BN, AM9S800604BX, AM9S800803BX, AM9S800804BX, AM9S800804CX, AM9S800805CX, AM9S801005CX, AM9S801205DX |
| GM9S92 | |
| GM9S96 / GC9S96 / AM9S96 / AC9S96 | GM9S960403AN, GM9S960603BN, GM9S960803BN, GM9S960804CN, GM9S960805CN, GM9S961005CN, GM9S961205DN, GC9S960403BN, GC9S960603BN, GC9S960804CN, GC9S961005CN, GC9S961205DN, AM9S960403AN, AM9S960603BN, AM9S960803BN, AM9S960804CN, AM9S960805CN, AM9S961005CN, AM9S961205DN |
| GR9S80 / GD9S80 / AR9S80 | GR9S800403AN, GR9S800403AX, GR9S800603AN, GR9S800603AX, GR9S800603BN, GR9S800603BX, GR9S800604BN, GR9S800604BX, GR9S800803BN, GR9S800803BX, GR9S800804BN, GR9S800804BX, GR9S800804CN, GR9S800804CX, GR9S800805CN, GR9S800805CX, GR9S801005CN, GR9S801005CX, GR9S801205DN, GD9S800403AN, GD9S800403AX, GD9S800603AN, GD9S800603AX, GD9S800804BN, GD9S800804BX, GD9S800805CX, GD9S801005CN, GD9S801005CX |
| GR9S92 / AR9S92 | GR9S920403AN, GR9S920603BN, GR9S920803BN, GR9S920804CN, GR9S920805CN, GR9S921004CN, GR9S921005CN, GR9S921205DN |
| GR9S96 / GD9S96 / AR9S96 | GR9S960403AN, GR9S960603BN, GR9S960803BN, GR9S960804CN, GR9S960805CN, GR9S961005CN, GR9S961205DN, GD9S960403BN, GD9S960603BN, GD9S960804CN, GD9S961005CN, GD9S961205DN, AR9S960403AN, AR9S960603BN, AR9S960803BN, AR9S960804CN, AR9S960805CN, AR9S961005CN, AR9S961205DN |
| GR9T80 / GD9T80 | GR9T800403AN, GR9T800403AX, GR9T800603AN, GR9T800603AX, GR9T800603BN, GR9T800603BX, GR9T800803BN, GR9T800803BX, GR9T800804BN, GR9T800804BX, GR9T800804CN, GR9T800804CX, GR9T800805CN, GR9T800805CX, GR9T800805DX, GR9T801004CN, GR9T801005CN, GR9T801005CX, GR9T801205DN, GD9T800403AX, GD9T800603AX, GD9T800603BX, GD9T800804BX, GD9T800805CX, GD9T801005CX |
| GR9T96 / GD9T96 | GR9T960303AN, GR9T960403AN, GR9T960603AN, GR9T960603BN, GR9T960803BN, GR9T960804CN, GR9T961004CN, GR9T961005CN, GR9T961205DN |
Where this comes from
- GM9S80/GC9S80 gas furnace installation instructions (IOG-2030B) , page 29
- GR9S92/GR9S96/GD9S96 gas furnace installation instructions (IOG-2037C) , page 44
Checked against the manufacturer's manual on 13 October 2026.
Other Goodman gas furnace codes
| Code | Meaning | What you can do |
|---|---|---|
| b2 | Blower motor size does not match the shared data | Call a pro |
| d0 | No shared data loaded on the control board | Call a pro |
| d4 | Invalid memory card data | 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 |
| EEF | Auxiliary (condensate) switch open | 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 |
| red light flashing rapidly | Electrical fault or configuration error (depends on model) | Call a pro |
See all configuration error codes on gas furnaces across brands.