F.354 — Burner in fault state: Gas modulation valve tolerance exceeded

What does F.354 mean?

The burner is in a fault state because the gas modulation valve tolerance is outside the permissible range. This affects gas flow control and combustion.

• Gas modulation valve tolerance outside permissible range
• Faulty gas fan unit

Click steps to track your progress.

1. 1

   Reset the boiler by briefly turning off and on its power supply.

2. 2

   If the fault persists, contact a qualified heating engineer for further diagnosis.

3. 3

   An engineer will need to replace the gas fan unit if the issue persists.