F.357 — Burner in fault state: Insufficient gas supply

What does F.357 mean?

The burner is in a fault state due to an insufficient gas supply. This can be caused by various issues from the gas shut-off valve to the gas line itself.

• Gas shut-off valve closed
• Contaminated input-side screen in the gas solenoid valve
• Incorrect static gas pressure or gas flow pressure
• Incorrectly sized on-site gas line
• Building pressure regulator leak
• Faulty cable to the fan unit
• Damaged ignition electrode insulation

Click steps to track your progress.

1. 1

   Check that the gas shut-off valve for the boiler is fully open.

2. 2

   Visually inspect the input-side screen in the gas solenoid valve for any contamination.

3. 3

   Reset the boiler by briefly turning off and on its power supply. If the fault persists, contact a qualified heating engineer or your gas provider.