BoilerFaultCodesYour boiler has lost communication with the sensor that monitors water returning from your radiators, often causing the system to stop working 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: Return sensor open circuit – check connections to return sensor are in place
What causes this fault?
This fault occurs when the boiler's main control board can no longer read the temperature of the water coming back from your radiators. The most common reason is that the internal sensor has developed an electrical failure or the connecting wires have become loose or damaged. Because the boiler cannot monitor the water temperature accurately, 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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