BoilerFaultCodesYour boiler has stopped working because it cannot accurately 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 sensor Sensor failed open or closed circuit
What causes this fault?
This fault occurs when the internal sensor responsible for monitoring the temperature of the water coming back into the boiler fails or loses its electrical connection. This is usually caused by the sensor's internal components degrading over time from constant heat cycles or because the wiring has become loose or corroded. Because the boiler can no longer safely tell how hot the water is, it shuts down to prevent the system from overheating.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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