Emergency Lockout
306 V on Worcester Bosch Greenstar 8000 Life/Style

Your boiler is still detecting a flame even after it has tried to shut off the gas, which is a safety conflict that requires a professional inspection.

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 signal after closing the fuel supply – the air/gas ratio control valve might need replacing

What causes this fault?

This fault occurs when the boiler's internal sensors continue to detect a flame even after the gas supply should have been cut off. The most common reason is a gas valve that has become stuck open or a faulty electrode that is incorrectly reporting a flame to the control board. Because the boiler cannot guarantee it can stop the flow of fuel, it shuts down immediately as a critical safety precaution.

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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