Carrier Furnace Error Code 13 Flash: How to Fix It

Q: What causes Carrier furnace error code 13 flash?

Error code 13 flash is caused by the high-limit safety switch tripping repeatedly due to overheating. Common causes include dirty air filters, blocked vents, faulty blower motor, restricted ductwork, or a malfunctioning limit switch.

Q: Is it safe to reset Carrier error code 13 flash?

You can attempt one reset after identifying and fixing the underlying cause of overheating. However, never repeatedly reset the system as this safety feature prevents dangerous overheating and potential fire hazards.

Q: How often should I change my furnace filter to prevent error 13?

Replace standard 1-inch filters every 1-3 months, depending on usage and home conditions. Homes with pets, allergies, or high dust levels may need monthly changes. Thicker pleated filters can last 3-6 months.

Q: Can a bad thermostat cause Carrier error code 13 flash?

While less common, a malfunctioning thermostat that causes rapid cycling or continuous operation can contribute to overheating. However, airflow restrictions are the most frequent cause of limit switch lockouts.

Q: How much does it cost to fix Carrier furnace error 13?

DIY fixes like filter replacement cost $10-30. Professional diagnosis and repair typically ranges from $150-500 depending on the root cause, with blower motor replacement being the most expensive repair at $300-500 including labor.

Abstract

Carrier furnace error code 13 flash indicates a limit switch lockout, meaning the high-limit safety switch has tripped 3 or more times during a single heating call. This critical safety feature protects your furnace from overheating and potential fire hazards by shutting down the system when temperatures exceed safe limits.