Goodman GMEC960803BN Error Code Red 1 Flash: Flame Sensed When No Flame Should Be Present
What Does Code Red 1 Flash Mean?
One red flash on the Goodman GMEC960803BN control board is a serious safety alert indicating that the flame sensor is detecting flame when the gas valve should be closed. This means either gas is flowing when it should not be, or the flame sensing circuit has a fault that is producing a false reading.
The most dangerous possibility is a gas valve stuck in the open position, which would allow gas to flow into the combustion chamber without a controlled ignition sequence. This creates a risk of unburned gas accumulation. A shorted flame sensor rod or wire can also cause this code by sending a false flame signal to the control board, even though no actual flame exists.
Improper wiring to the gas valve is another possible cause, particularly after a recent repair or control board replacement. Regardless of the cause, this code should be treated as a safety emergency. Turn off the gas supply valve (handle perpendicular to the pipe) and shut off the furnace at the circuit breaker. Do not attempt to restart the furnace until a qualified technician has diagnosed and resolved the issue.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Gas valve stuck open | Most common | ✗ Call a pro → |
| Shorted flame rod or wire | Common | ✗ Call a pro → |
| Improper wiring to gas valve | Common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- The furnace shows 1 red flash — call immediately
- You smell gas near the furnace
- The gas valve appears to be stuck or leaking
✓ Verified against manufacturer service manual — March 2026