F.350, F.351 — Burner in fault state: Ionization current outside permissible range

What does F.350, F.351 mean?

The burner is in a fault state because the ionization current is outside the permissible range. This indicates an issue with flame detection and safety.

• Ionization current lies outside the permissible range
• Faulty BCU burner control 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 recurs, contact a qualified heating engineer for further diagnosis.

3. 3

   An engineer may need to replace the BCU burner control unit if the issue persists.