BoilerFaultCodesTechnical description
Fault detected with the pump. Check pump connections, water flow, or replace pump.
What causes this fault?
This fault occurs when the boiler's internal computer detects that water is not circulating through the heat exchanger correctly. The most common reasons are a mechanical failure of the pump motor, a buildup of sludge blocking the internal pipework, or a loose electrical connection between the pump and the main control board.
This issue is frequently seen in autumn when heating systems are switched back on after being idle all summer, which can cause the pump's internal bearings to seize up.
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.
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