Lennox HVAC Error Code E274: How to Fix It

Q: What causes Lennox error code E274?

E274 is caused by three consecutive failed ignition attempts. Common causes include a dirty flame sensor, clogged air filter, faulty igniter, gas supply issues, or problems with the ignition control module.

Q: How do I reset Lennox error code E274?

Reset E274 by turning off the power to your HVAC unit for 5 minutes, then turning your thermostat to OFF, waiting another 5 minutes, and setting it back to HEAT. This clears the lockout condition.

Q: Is it safe to keep trying to restart when I get E274?

No, do not repeatedly try to restart. The E274 lockout is a safety feature that prevents gas buildup. Address the underlying cause before attempting to restart the system.

Q: Can a dirty air filter cause E274 error?

Yes, a severely clogged air filter restricts airflow, which can affect the heat exchanger temperature and pressure switches, leading to ignition failures and E274 errors.

Q: How much does it cost to fix Lennox E274 error?

DIY fixes like cleaning the flame sensor or replacing the air filter cost $10-30. Professional repairs range from $150-500 depending on the faulty component, with ignition control modules and gas valves being more expensive to replace.

Abstract

Lennox HVAC error code E274 indicates an ignition lockout has occurred after 3 failed ignition attempts. This safety feature prevents gas buildup and potential hazards when your furnace cannot properly ignite, requiring immediate attention to restore heating function.