Emergency
Fast flash on Worcester Bosch Greenstar 42CDi

Your boiler is still sensing a flame even after it has been told to turn the gas off, which is a safety conflict.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description

Flame detected after gas shut off.

Engineer required

This is a emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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