BoilerFaultCodesYour boiler's internal pump is detecting a communication error or is set to the wrong operating mode, meaning it cannot circulate water properly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Pump switch mode
What causes this fault?
This fault occurs when the boiler's control board loses touch with the internal pump or notices it is running in the wrong setting. The most common reason is an electronic communication failure between the pump and the main computer, often caused by a loose connection or a failing pump motor. Without this connection, the boiler cannot safely move hot water around your system, so it shuts down to prevent overheating.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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