How much does it cost to fix Alpha error code Overheat Thermostat operates?

Typical repair cost for the Alpha Overheat Thermostat operates fault is £150-£300 including labour.

Overheat Thermostat operates High

Alpha Overheat Thermostat operates Fault Code

Q: What does the Alpha Overheat Thermostat operates fault code mean?

Your boiler has detected that it is running too hot and has automatically switched itself off to prevent any damage or safety issues.

Also written as OVERHEATTHERMOSTATOPERATES — same fault.

The Alpha Overheat Thermostat operates fault code means: your boiler has detected that it is running too hot and has automatically switched itself off to prevent any damage or safety issues.. It appears on 5 Alpha models in our database.

Technical description: Automatically switches the boiler off in the event of the boiler overheating. Turns the pilot off.

Typical repair cost £150-£300 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Alpha models that show the Overheat Thermostat operates fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Alpha Overheat Thermostat operates fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026