BoilerFaultCodesYour boiler has detected that water is failing to circulate correctly through the system, which will prevent it from heating your home or providing hot water.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: The diagnostics will indicate the nature of the fault to assist a speedy and effective repair
What causes this fault?
This fault occurs when the boiler's internal sensors detect that water is not moving through the heat exchanger at the required rate, often due to a mechanical failure or a blockage. The most common reason is a seized or worn-out circulation pump, though it can also be caused by air trapped in the system or a build-up of sludge obstructing the flow. Without this movement, the boiler must shut down to prevent the unit from overheating and causing internal damage.
This issue is frequently seen at the start of autumn when heating systems are switched back on after being idle all summer, which can cause the pump components to seize.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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