23.1
Stuck main pressure switch
This code typically points to
- Obstructed pressure tube
- Pressure switch stuck closed
Next checks to confirm
- Verify switch state before inducer run
- Inspect tubing and ports
- Replace switch only after tubing is proven clear
Escalation
Persistent false-closed reading with proven tubing and switch state points toward board input fault.
Reset behavior
Active fault clears when pressure-switch startup proofing normalizes.
Urgent
Fix now