What It Means
Limit or flame rollout switch open longer than 3 minutes or 10 limit trips in high heat.
Carrier Furnace
Carrier Furnace Error Code 13
Troubleshooting guide for the Carrier Furnace system fault 13.
Possible Causes
- Restricted airflow from dirty filter or blocked registers.
- Faulty blower motor or failed run capacitor.
- Open limit or flame rollout switch.
- Cracked or obstructed heat exchanger.
Not sure which one it is — or if it's none of these? Try ACLogics today.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
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Full Diagnosis
Limit Circuit Lockout. Lockout occurs if the limit or flame rollout switch is open longer than 3 minutes or after 10 successive limit trips during high heat; auto reset after 3 hours.
All Recorded Causes
Check for restricted airflow (dirty filter, blocked registers). Inspect limit switch and flame rollout switch for continuity. Verify blower motor operation. Check heat exchanger for cracks or obstructions.
Verify Before Replacing Parts
- Confirm the exact Carrier model family and furnaces context before acting on a generic code description.
- Walk the entire heating sequence in order instead of jumping straight to the reported code, watching for check for restricted airflow (dirty filter, blocked registers).
- Verify each safety device and prove where the sequence stops under live operation, including whether inspect limit switch and flame rollout switch for continuity.
- After the correction, run the system long enough to confirm the furnaces fault does not return under normal load.
Still unsure about this fault?
ACLogics walks you through Carrier Furnace diagnostics step-by-step — so you confirm the cause before swapping parts.
