Lennox HVAC Error Code E31: How to Fix It

Q: Can I reset Lennox error code E31?

Yes, turning off power to the system for 5-10 minutes and then restoring it may clear the error. However, you must address the underlying cause (e.g., dirty filter) to prevent recurrence.

Q: What causes E31 on Lennox HVAC?

E31 is caused by the heat strips overheating. Common reasons include a dirty air filter, closed or blocked vents, a faulty high-limit switch, or a malfunctioning blower motor.

Q: Is it safe to run my system with error E31?

No. The system shuts down the heat strips to prevent fire risk. Running it could cause damage or safety hazards. Troubleshoot and fix the issue before operating.

Q: How much does it cost to fix E31?

If you DIY, costs are minimal (e.g., $10-$30 for a filter). Professional service may cost $150-$300 for diagnostic and repair, plus parts if needed.

Q: Can a dirty filter cause E31?

Yes, a dirty filter is the most common cause. It restricts airflow over the heat strips, causing them to overheat and trigger the safety limit switch.

Abstract

Error code E31 on your Lennox HVAC system indicates that the auxiliary heat strips have overheated. This is a safety shutdown to prevent damage or fire. Common causes include restricted airflow, a dirty filter, or a faulty limit switch.