BoilerFaultCodesYour boiler has detected an issue with the sensor that monitors the temperature of the water leaving the unit, causing it to shut down as a safety precaution.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flow Thermistor
What causes this fault?
This fault occurs when the boiler's control system loses communication with the sensor that measures the heat of the water departing the unit. It is usually caused by the internal sensor failing electrically or developing a crack, though it can also be triggered by loose internal wiring connections. Depending on the failure, the boiler may detect that the water is dangerously hot or that the sensor is missing entirely, leading to an immediate shutdown.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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