How much does it cost to fix boiler error code Lock-out (Flashing light)?

Typical repair cost for the boiler Lock-out (Flashing light) fault is £120-250 including labour.

Lock-out (Flashing light) High

Boiler Fault Code Lock-out (Flashing light)

Also written as LOCKOUTFLASHINGLIGHT — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Lock-out (Flashing light) appears across 1 boiler brand and 4 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has stopped working because it cannot light the internal flame or maintain it, meaning you currently have no heating or hot water. (As reported on Worcester Bosch 24i/28i Junior)

Pick your boiler brand for the Lock-out (Flashing light) fix

Worcester Bosch Lock-out (Flashing light) 4 models

Source

Information for the Lock-out (Flashing light) fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026