3 flashes
Pressure switch stuck closed
This code typically points to
- Stuck switch contacts
- Misrouted tubing
- Condensate, wind, or vent effect holding proof circuit in abnormal state
- Board seeing closed circuit at wrong time
Next checks to confirm
- Verify switch state before inducer run
- Inspect tubing and venting
- Verify switch opens/closes correctly with inducer cycle
Escalation
If switch behavior is normal at the component but board still reads closed, board fault is likely.
Reset behavior
Clears when startup proofing becomes normal.
Urgent
Fix now