Fault F8 (Detailed 148) — Burner fault: gas valve closes too late

What does F8 mean?

The burner is in fault mode because the gas valve closes too late. This is a critical safety fault as it means gas flow is not being cut off promptly, which can lead to unsafe gas accumulation.

• Gas valve closes too late

Click steps to track your progress.

1. 1

   Check the gas valve for any signs of mechanical sticking or delayed operation.

2. 2

   Inspect both the control wiring and connections leading to the gas valve for looseness or damage.

3. 3

   Press the reset button R on your boiler.

4. 4

   If the fault persists, immediately contact a qualified gas safe engineer to inspect or replace the gas valve.