How much does it cost to fix boiler error code Overheat thermostat activated?

Typical repair cost for the boiler Overheat thermostat activated fault is £150-300 including labour.

Overheat thermostat activated High

Boiler Fault Code Overheat thermostat activated

Also written as OVERHEATTHERMOSTATACTIVATED — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Overheat thermostat activated appears across 1 boiler brand and 4 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 has become dangerously hot, likely due to a circulation problem or a faulty safety sensor. (As reported on Halstead Finest Gold)

Pick your boiler brand for the Overheat thermostat activated fix

Halstead Overheat thermostat activated 4 models

Source

Information for the Overheat thermostat activated 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