BoilerFaultCodesYour boiler has detected a problem with the sensor that monitors the temperature of the water returning to the unit, causing it to stop for safety.
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 error – reset the boiler
What causes this fault?
This fault occurs when the boiler's control board stops receiving a reliable signal from the sensor that monitors the cool water coming back from your radiators. The most common reason is that the sensor has developed an internal electrical fault or the wiring connecting it to the main computer has become loose or damaged. Because the boiler can no longer safely track how much heat to add to the water, it shuts down to prevent overheating.
DIY fix possible
Press the Reset button on the boiler control panel onceWait for the boiler to complete its restart sequenceIf the code persists, contact a Gas Safe registered engineer
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 80-01 — 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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