BoilerFaultCodes LOCKOUT LIGHT FLASHING High
Boiler Fault Code LOCKOUT LIGHT FLASHING
Also written as LOCKOUTLIGHTFLASHING — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code LOCKOUT LIGHT FLASHING 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 failed to light or stay lit, which has triggered a safety shutdown. (As reported on Worcester Bosch Greenstar 15sbi)
Pick your boiler brand for the LOCKOUT LIGHT FLASHING fix
Source
Information for the LOCKOUT LIGHT FLASHING 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