BoilerFaultCodesYour boiler has stopped working because it cannot correctly measure the temperature of the water returning from your radiators.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Return temperature sensor error (Return temperature sensor not connected or defective)
What causes this fault?
This fault occurs when the boiler's internal computer loses communication with the sensor that monitors the cool water coming back from your radiators. The most common reason is that the sensor has physically failed due to age or the electrical connection has become loose or corroded. Because the boiler can no longer verify the water temperature, it shuts down as a safety precaution to prevent overheating.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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