BoilerFaultCodesYour boiler has detected that a temperature sensor is not working correctly, which has caused the system to stop running to prevent overheating.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fault on Temperature Sensor
What causes this fault?
This fault occurs when the boiler's control board can no longer read accurate information from the flow temperature sensor. The most common reason is that the internal thermistor has physically failed or developed a short circuit, meaning the boiler can no longer safely monitor how hot the water is getting. In some cases, it may also be caused by loose or damaged wiring connecting the sensor to the main control unit.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like 25 — no call-out fees, no surprises.
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