Goodman GMVC960803BN Error Code E12: Redundant Relay Open
What Does Code E12 Mean?
Error code E12 on the Goodman GMVC960803BN indicates that the redundant gas valve relay — a secondary relay on the integrated control module that is part of the gas valve safety circuit — is detected as open when it should be closed. The furnace cannot fire because the gas valve circuit cannot be completed.
This furnace uses a dual-relay design for the gas valve circuit as a safety feature. One relay commands the gas valve to open during normal operation; the redundant relay provides a backup safety shutoff path. The control module monitors both relays. When the redundant relay fails in the open position, it breaks the circuit path and prevents the main gas valve relay from being able to energize the valve.
A faulty relay on the control board is the most likely cause. Because the relay is part of the integrated control module rather than a separate replaceable component, the entire control board typically requires replacement. A technician must confirm the diagnosis before ordering parts.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Faulty redundant gas valve relay on control board | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- E12 is present — a technician must confirm that the control board's redundant relay has failed before the board is replaced
- Control board replacement is required — this is a specialized repair that requires a qualified HVAC technician
✓ Verified against manufacturer service manual — March 2026