Technical description
Ignition, pilot or flame proving fault
What causes this fault?
This fault happens when the boiler attempts to start up but cannot successfully ignite the gas or detect a steady flame. It is often caused by a blocked pilot light burner or a worn-out ignition spark, which prevents the main burner from firing up safely. In some cases, the internal control board may also fail to recognise that the flame is lit, prompting the system to shut down for your protection.
This issue often surfaces during the first cold spell of autumn when the boiler is worked harder after being mostly idle throughout the summer.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.