23
Pressure switch did not open
This code typically points to
- Obstructed pressure tubing
- Pressure switch stuck closed
- Moisture/debris in tubing or trap on condensing units
Next checks to confirm
- Verify switch state with inducer off
- Inspect tubing for blockage/water
- Prove switch operation with manometer if needed
Escalation
If switch state is correct but board still reports fault, control/input issue becomes possible.
Reset behavior
Clears when proper switch-open condition is restored.
Urgent
Fix now