33
Limit circuit fault
This code typically points to
- Dirty filter/restricted duct
- Failed blower motor or capacitor
- Loose blower wheel
- Rollout switch open
- Inadequate combustion air
Next checks to confirm
- Separate airflow problem from rollout/combustion problem
- Check static, temp rise, blower operation, filter, wheel
- Inspect rollout/manual-reset switch and vent path
Escalation
If open longer than 3 minutes changes to lockout code 13; rollout/manual-reset event is a harder safety problem.
Reset behavior
Blower runs 4 minutes or until switch remakes, whichever is longer; escalates to 13 if open >3 minutes.
Urgent
Fix now