BoilerFaultCodes OVERHEAT LOCKOUT INDICATOR High
Boiler Fault Code OVERHEAT LOCKOUT INDICATOR
Also written as OVERHEATLOCKOUTINDICATOR — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code OVERHEAT LOCKOUT INDICATOR appears across 1 boiler brand and 8 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has switched itself off because it got too hot, which is a safety feature designed to prevent overheating damage. (As reported on Halstead Best 80)
Pick your boiler brand for the OVERHEAT LOCKOUT INDICATOR fix
Source
Information for the OVERHEAT LOCKOUT INDICATOR 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