BoilerFaultCodesYour boiler is having trouble communicating with the internal pump that moves hot water around your heating system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Communication fault: Variable speed heating circuit pump
What causes this fault?
This fault occurs when the boiler's main control board loses its digital connection with the internal pump, preventing the system from synchronising water flow with heat demand. The most common reason is a failure in the pump's internal electronic module or a loose connection in the low-voltage communication data cable. In some cases, a power surge or moisture ingress can damage the circuitry responsible for these signals.
This fault is frequently seen at the start of autumn when a pump that has remained stationary all summer is suddenly required to ramp up to full speed.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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