BoilerFaultCodes Lockout will not reset High
Boiler Fault Code Lockout will not reset
Also written as LOCKOUTWILLNOTRESET — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Lockout will not reset 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 detected that it is dangerously overheated or has run without enough water and will not restart until it has cooled down completely. (As reported on Baxi 800 Heat (range))
Pick your boiler brand for the Lockout will not reset fix
Source
Information for the Lockout will not reset 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