31
High-heat pressure switch or relay did not close or reopened
This code typically points to
- High-heat pressure switch not proving
- Relay fault
- Gas-valve miswire
- Condensate issues or vent restrictions can indirectly create high-fire proving complaints
Next checks to confirm
- Verify high-heat proving sequence and switch closure
- Verify relay/gas-valve wiring
- Inspect venting/condensate path
Escalation
Repeated code after proofing checks points toward relay/control fault.
Reset behavior
Active fault clears when proper proving returns.
Urgent
Fix now