BoilerFaultCodesYour boiler's internal thermometer that measures the water returning from your radiators has developed a fault and can no longer read the temperature correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Return temp. sensor is faulty
What causes this fault?
This fault occurs when the sensor responsible for measuring the water coming back from your radiators fails to send a reliable signal to the boiler's control board. The most common reason is that the internal electrical components of the sensor have worn out or corroded over time, or a wire has become loose or damaged. Because the boiler can no longer verify the water temperature, it shuts down as a safety precaution to prevent overheating.
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 1025 — 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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