Safety thermostat activated High

Baxi Safety thermostat activated Fault Code

Also written as SAFETYTHERMOSTATACTIVATED — same fault.

The Baxi Safety thermostat activated fault code means: your boiler has detected that it got too hot and has automatically switched itself off to stay safe.. It appears on 1 Baxi 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: Press reset button on safety thermostat. If regular resetting is required, investigation is necessary. Check continuity across terminals (>1.5 ohm indicates fault).
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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Baxi models that show the Safety thermostat activated fault code

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

Source

Baxi Safety thermostat activated fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.

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