Overheat thermostat (240XP) High

Alpha Overheat thermostat (240XP) Fault Code

Also written as OVERHEATTHERMOSTAT240XP — same fault.

The Alpha Overheat thermostat (240XP) fault code means: your boiler has detected that it got too hot and has automatically shut itself down for safety, meaning your pilot light has gone out and needs to be relit.. It appears on 1 Alpha model in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: The pilot is turned off and will have to be relit
Typical repair cost £120-250 (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 (240XP) fault code

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

Source

Alpha Overheat thermostat (240XP) 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