Keep the furnace off. Do not reset a rollout switch. If you smell gas or a carbon-monoxide alarm sounds, leave the building and contact emergency services or the gas utility.
What does Carrier code 13 mean?
Carrier furnace code 13 means the limit or flame-rollout circuit opened repeatedly and the furnace locked out on the supported control family. Confirm the model number and diagnostic chart inside the furnace door before replacing parts.
What causes Carrier code 13?
- A blocked flue or combustion-air path
- A burner or gas-pressure problem
- A damaged or restricted heat exchanger
Can I troubleshoot Carrier code 13?
Keep the furnace off. Do not reset a rollout switch. If you smell gas or a carbon-monoxide alarm sounds, leave the building and contact emergency services or the gas utility.
How much does Carrier code 13 cost to fix?
A heat exchanger replacement typically costs between $500 and $3,500 nationally.
When should I call a technician?
Leave the furnace off and call a licensed technician for a combustion-safety inspection.
Symptoms this code causes
Sources and model scope
Fault codes vary by model and control board. Confirm the diagnostic chart inside your furnace panel or the official manual before acting.
Scope used here: Carrier-family two-stage controls covered by troubleshooting guide 58-3T.
- Carrier Corporation: Deluxe 2-Stage Gas-Fired Induced-Combustion Furnaces — Troubleshooting Guide
58-3T · Carrier-family two-stage furnace controls covered by document 58-3T; codes vary on other boards and model generations.
Compiled by Warmlo Editorial · Reviewed August 2026
This is general information, not professional advice. Gas, electrical, and combustion repairs can be dangerous — when in doubt, call a licensed technician.