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 sensor error
What causes this fault?
This fault occurs when the internal sensor responsible for monitoring the temperature of the water coming back from your radiators stops sending a reliable signal to the main computer. The most common reason is that the sensor itself has developed an electrical fault or has been damaged by wear and tear, preventing the boiler from knowing if it is safe to continue firing. In some cases, it can also be caused by loose or damaged wiring connecting the sensor to the control board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like 40 — no call-out fees, no surprises.
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Could it be time for a new boiler?
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