BoilerFaultCodes HIGH High
Boiler Fault Code HIGH
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code HIGH 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 stopped working because the water pressure inside the system has become too high, which is a safety mechanism to prevent damage. (As reported on Atag Premier)
Pick your boiler brand for the HIGH fix
Source
Information for the HIGH 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