BoilerFaultCodesYour boiler has detected a problem with one of its internal temperature sensors, which prevents it from monitoring the water returning to the unit 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 sensor S2 defective
What causes this fault?
This fault occurs when the boiler's control board loses communication with the sensor that monitors water coming back from your radiators. This is typically caused by the internal component failing due to age or a loose connection in the electrical wiring, meaning the boiler can no longer safely regulate its temperature.
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 E11 — 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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