BoilerFaultCodes Heat exchanger overheat High
Boiler Fault Code Heat exchanger overheat
Also written as HEATEXCHANGEROVERHEAT — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Heat exchanger overheat appears across 1 boiler brand and 1 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 parts inside are getting dangerously hot and has automatically switched itself off to prevent permanent damage or a safety hazard. (As reported on Worcester Bosch Greenstar 12i System)
Pick your boiler brand for the Heat exchanger overheat fix
Source
Information for the Heat exchanger overheat 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