F62 Fault — Gas valve delayed shutdown

What does F62 mean?

The boiler detected a delay in the gas valve shutting off after the flame should have extinguished. This indicates the flame signal remained present for too long.

• Gas valve defective
• PCB defective
• MK1 thermal fuse with a high resistance

Click steps to track your progress.

1. 1

   Perform a local tightness test on the gas valve to check if it's passing gas when it shouldn't be (requires specialist tools).

2. 2

   On MK1 systems, check the thermal fuse for high resistance (requires specialist tools).

3. 3

   If the gas valve passes the tightness test, the PCB may be faulty (contact a technician).