BoilerFaultCodesYour boiler has detected a problem with the internal sensor that monitors water returning from your radiators, meaning it cannot safely regulate its temperature and has stopped working.
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 open-circuit. Sensor not or badly connected.
What causes this fault?
This fault occurs when the boiler's control system loses communication with the sensor that monitors water coming back from your radiators. The most common reason is that the sensor itself has developed an internal electrical failure or the wiring connecting it to the main control board has come loose or become damaged. Without this data, the boiler cannot accurately balance its heat output, so it shuts down as a safety precaution.
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 E.00 – .04 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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