BoilerFaultCodesYour boiler has stopped working because one of its internal heat sensors is reporting a technical error or has failed.
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 S1.
What causes this fault?
This fault occurs when the boiler's control board loses communication with the flow temperature sensor or receives an illogical reading. The most common reason is that the internal sensor has developed an electrical fault, or the wiring connecting the sensor to the main board has become loose or damaged.
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 F031 — 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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