Goodman GMVM970803BN Error Code E4: Flame Detected When No Flame Should Be Present
What Does Code E4 Mean?
An E4 code on the Goodman GMVM970803BN indicates that the flame sensor is detecting a flame signal at a time when no flame should exist — either before the gas valve has been commanded open or after it should have closed. This is a critical safety condition because it suggests either an actual uncontrolled flame in the burner area or an electrical fault generating a false flame signal. The integrated control module responds by running both the inducer and circulator blowers continuously as a safety measure while refusing to allow any new ignition attempts.
The most likely cause is a short circuit in the flame sensor wiring or the sensor grounding against the burner assembly, which creates a false electrical signal that mimics flame detection. The flame rectification circuit used by this furnace is very sensitive to electrical leakage — even a small unintended current path from the sensor lead to ground can trigger this fault. A gas valve that closes too slowly, allowing gas to continue flowing briefly after the valve should be shut, can also produce a lingering burner flame that triggers the code. In rare cases, residual combustion heat in the burner area after shutdown can cause a momentary false reading.
This fault involves both the gas system and the flame detection safety circuits, making it entirely a professional service issue. The technician must inspect the flame sensor and its wiring for shorts or ground faults, verify the gas valve closes promptly when de-energized, and check for any signs of lingering flame after shutdown.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Short to ground in flame sense circuit | Most common | ✗ Call a pro → |
| Lingering burner flame | Common | ✗ Call a pro → |
| Slow closing gas valve | Common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- Call a technician immediately — a flame signal when no flame should be present is a serious safety condition involving the gas system that requires professional diagnosis
- The technician must test the flame sensor circuit for shorts to ground, verify the gas valve closes properly, and determine whether the sensor, wiring, or gas valve needs replacement
✓ Verified against manufacturer service manual — March 2026