High Lockout
Burner On neon going out on Glow-worm Hideaway 40B

Your boiler is failing to detect its own flame correctly, causing it to shut down shortly after trying to start.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

The correct working of the flame supervision is shown by the 'Burner On' neon going out and the ignition sequence starting up. After a short period the boiler will shut down.

What causes this fault?

This fault happens when the boiler's internal safety system fails to confirm that a flame has successfully lit. It is usually caused by a worn-out sensor that can no longer 'see' the flame, or a fault in the control board that prevents the ignition sequence from completing. When the boiler cannot verify it is burning gas safely, it shuts down immediately as a protective measure.

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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