What does the "B Fail" Error Mean?

by Coby Poluk on September 20, 2023 Categories: Troubleshooting

A "B Fail" error on your thermostat means your burner attempted to ignite for 3 full cycles without success.

The burner control module generally displays a flashing fault code to help distinguish this issue.

Please read our burner troubleshooting guide to help diagnose the cause of this error.

Burner Troubleshooting Guide