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's Integrated Control Module means the flame-sensing circuit is reading a flame at a time when the burners should be off. The board expects no flame signal during standby and pre-ignition; sensing one there tells it something is wrong with either the gas supply to the burners or the flame-sense circuit itself.
The most serious possibility is a gas valve that is stuck open or leaking through, allowing gas to keep burning when the board has commanded it off. The board can also read a false flame if the flame rod or its wire is shorted to ground, which mimics a flame signal electrically. Because the first case involves uncontrolled gas, this is treated as a high-severity safety fault and the furnace will not operate.
This is the opposite failure mode from the low-flame and no-flame codes. Where rapid amber (low flame sense) and red 7/8 (ignition lockouts) mean the board cannot confirm a flame that should exist, red 1 flash means it detects a flame that should not exist — which is why the safe response is to stop gas flow and get it inspected.
What You'll Notice
- The furnace will not start a normal cycle and the board flashes red once
- Burners may stay lit or relight when there is no call for heat
- You may smell gas near the furnace if the valve is passing gas
- The fault can appear at the end of a cycle when the flame should have gone out
- The furnace refuses to begin a new ignition sequence
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 → |
How This Is Diagnosed
Because a false or unexpected flame signal can mean uncontrolled gas, safety comes first: the gas supply is shut off before investigation. A technician then determines whether the signal is real or electrical — checking whether the burners are actually still burning (pointing to a gas valve leaking through or stuck open) versus a shorted flame rod or flame-sense wire producing a false reading. Gas valve testing or replacement and any wiring repair are professional tasks. Do not attempt gas valve work yourself.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The burners stay lit or reignite when there is no call for heat
- You smell gas near the furnace
- The single red flash returns after power is cycled
- Any situation where you suspect the gas valve is not fully closing
Frequently Asked Questions
Is one red flash on my Goodman furnace dangerous?
It can be. It means the board senses a flame when there should be none, which may indicate a gas valve that is not fully closing. Shut off the gas supply and have a technician inspect it before running the furnace.
Could this just be a wiring problem instead of a gas valve?
Yes — a shorted flame rod or flame-sense wire can create a false flame signal. But because a stuck-open gas valve is also possible and involves uncontrolled gas, it should be diagnosed by a professional rather than assumed to be minor.
✓ Verified against manufacturer service manual — March 2026