Your boiler has detected a problem with its internal temperature sensor, which means it cannot safely monitor the water temperature and has stopped working to prevent damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Sensor fault S0.
What causes this fault?
This fault occurs when the boiler's main temperature sensor sends an incorrect or missing signal to the control board. The most common reason is that the sensor itself has developed an internal electrical failure, but it can also be caused by loose wiring or water damage on the sensor's connection points.
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 F010 — 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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