High
lock-out on Worcester Bosch 24si II

Your boiler is failing to light the flame, which means it has stopped working to keep you safe.

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 burner goes out but, after a short pause, the appliance will attempt to restart and spark for 10 seconds and then 'lock-out'. Occurs if the gas service cock is turned off or if the burner does not light.

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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