BoilerFaultCodesYour boiler has detected a communication error with its internal sensors or control unit that has lasted for more than five seconds.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: With 5 seconds time delay for fault message; message will be issued, if a fault persists for at least 5 seconds
What causes this fault?
This fault occurs when the boiler's central brain loses contact with the sensors that monitor water temperature. It is usually caused by a loose connection in the internal wiring or a physical failure within the temperature sensor itself, meaning the boiler can no longer safely verify how hot it is. In some cases, the control board may be unable to process the data it receives, leading to a total communication breakdown.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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