High
Ignition lockout on Worcester Bosch 24si II

Your boiler has stopped working because it failed to light the flame, which means your heating and hot water have turned off for safety.

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 fault indicator will flash slowly (approximately once per second). The burner fails to light after 5 attempts and the electricity supply to the gas valve is interrupted.

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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