BoilerFaultCodesYour boiler has detected a fault with the sensor that monitors water temperature returning to the unit, meaning it cannot operate safely or efficiently.
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 short-circuit. Sensor not connected or badly connected.
What causes this fault?
This fault occurs when the boiler's internal computer loses the ability to read the temperature of the water coming back from your radiators. The most common reason is that the sensor itself has suffered a mechanical failure or the electrical wiring connecting it to the main control board has come loose or become damaged.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like E.00 – .05 — 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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