BoilerFaultCodesYour boiler has detected a problem with the temperature sensor that monitors the water returning from your radiators, preventing the system from operating correctly.
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 error
What causes this fault?
This fault occurs when the internal computer loses communication with the sensor that monitors water temperature coming back from your radiators. The most common reason is that the sensor has physically failed or developed an electrical fault, though it can also be caused by loose or damaged wiring connecting the sensor to the main control board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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