Boiler Fault Code Boiler lockout indicator ON

Also written as BOILERLOCKOUTINDICATORON — same fault.

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

Fault code Boiler lockout indicator ON appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has shut itself down for safety reasons and needs to be manually restarted to resume heating and hot water. (As reported on Glow-worm Betacom)