BoilerFaultCodesYour boiler has detected a problem with its primary temperature sensor and has shut down as a safety precaution.
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 main flow sensor sends an irregular electrical signal to the control board, suggesting the sensor has either failed or is disconnected. The most common reason is that the internal component responsible for monitoring water temperature has physically degraded over time or a wire has become loose. Because the boiler can no longer accurately track how hot the water is getting, it shuts down to prevent the system from overheating.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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