BoilerFaultCodesWhat the manual says
Manufacturer manualN/A
What causes this fault?
This fault occurs when the boiler's control system detects that the internal pump is not rotating or circulating water effectively. The most common reason is that debris or magnetite from the heating system has jammed the pump's internal components, though it can also be caused by a mechanical failure of the motor or a communication error starting from the control board.
This issue is frequently seen at the start of autumn when heating is turned back on after being idle all summer, as stagnant debris is more likely to settle and seize the pump.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Avoid the next call-out bill
A cover plan would handle faults like A5: no call-out fees, no surprise bills.
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