BoilerFaultCodesTechnical description
Burner Lockout fault (gas supply, electrodes, flame sensor, or gas valve).
What causes this fault?
This fault occurs when the boiler attempts to start up but fails to detect a sustained flame after several attempts. It is usually caused by a lack of gas reaching the burner, worn-out sparking electrodes that can no longer create a light, or a dirty sensor that cannot 'see' the flame even if it is lit.
This issue often surfaces during the first cold snap of autumn when the boiler is pushed to work harder after sitting idle all 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.
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