Carrier Furnace Error Code 33 Flash: How to Fix It

Q: What does Carrier error code 33 flash mean?

Carrier error code 33 flash means the high-limit switch has opened due to restricted airflow or blower motor failure. This safety feature prevents the furnace from overheating.

Q: Can I reset Carrier error code 33 flash myself?

You can reset the error after fixing the underlying cause (usually restricted airflow). Simply turn off the thermostat for 5 minutes, then turn it back to heat. However, you must address the root cause first.

Q: Why does my Carrier furnace keep getting error code 33?

Recurring error code 33 typically indicates a dirty air filter, blocked vents, failing blower motor, or ductwork problems. Check and replace your air filter first, as this fixes the issue in most cases.

Q: Is Carrier error code 33 flash dangerous?

The error itself is a safety feature protecting your furnace from damage. However, the underlying causes (restricted airflow, overheating) need immediate attention to prevent potential furnace damage or safety hazards.

Q: How often should I change my furnace filter to prevent error code 33?

Replace your furnace filter every 1-3 months depending on usage, pets, and air quality. During heavy heating season, check monthly. A clean filter is the best prevention for error code 33.

Abstract

Carrier furnace error code 33 flash indicates the high-limit switch has opened due to restricted airflow or a failed blower motor. This is a critical safety issue that shuts down your furnace to prevent overheating and potential damage.