Emergency Lockout
FA on Worcester Bosch ZWB 7-25

Your boiler has detected that a flame is still burning inside the unit even though it should have turned off, which is a safety concern that requires an immediate professional check.

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 has been shut off.

What causes this fault?

This fault occurs when the boiler's internal sensors continue to detect a flame even after the system has instructed the gas to stop flowing. The most common reasons are a sticking gas valve that hasn't fully closed or a faulty detection electrode that is sending a false signal back to the main control board.

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.

Find a Gas Safe engineer
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Related fault codes

EAView →E9View →

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