E223
Low pressure switch failed open
This code typically points to
- Vent restriction
- Inducer issue
- Pressure tubing or switch problem
Next checks to confirm
- Check pressure switch closing pressure on heat call
- Measure operating pressure in inches w.c.
- Inspect vent and inducer for restriction or proper operation
Escalation
Heat sequence fault
Reset behavior
Resumes normal operation after fault clears.
Urgent
Fix now