2+4
Low pressure switch failed closed
This code typically points to
- Stuck contacts
- Miswired switch
- False proving due to tubing or water issue
Next checks to confirm
- Verify switch is open before inducer start
- Inspect tubing and porting
- Confirm switch state against actual inducer operation
Escalation
Heat sequence will not proceed correctly
Reset behavior
Clears once switch state is corrected and sequence is restarted.
Urgent
Fix now