BoilerFaultCodesYour boiler has detected a problem with the sensor that monitors the temperature of the water returning from your heating system, causing it to stop running for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Return thermistor fault
What causes this fault?
This fault occurs when the internal control board loses communication with the sensor that monitors water returning from your radiators. It is usually caused by the sensor's internal components wearing out over time or a loose connection in the internal wiring, preventing the boiler from safely regulating its temperature.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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