Green ON / Red FLASH
Pressure switch closed fault (stuck closed when inducer is off)
This code typically points to
- Pressure switch contacts stuck closed
- Water/condensate in pressure tubing causing false closed reading
- Inducer relay held on unexpectedly
- Wiring short in pressure-switch circuit
Next checks to confirm
- Verify pressure switch is open at rest before inducer starts
- Inspect pressure-switch tubing/port for water, blockage, or kinks
- Verify inducer is not being energized out of sequence and switch circuit is not shorted
Escalation
If switch is mechanically open and wiring is normal but board still reads closed, the fault shifts toward board input or relay/control sequencing.
Reset behavior
Clears when startup proofing sequence sees the switch open when expected.
Urgent
Fix now