BoilerFaultCodesYour boiler's internal pump, which moves water through your radiators, has encountered an electrical or mechanical fault and cannot circulate heat.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Status internal heating pump error
What causes this fault?
This fault occurs when the boiler's control board detects that the internal pump is either not spinning or not receiving power. The most common reasons are a mechanical seizure caused by a build-up of system debris or an electrical failure within the pump’s motor or wiring.
This issue is frequently seen at the start of autumn when a pump that has been sitting idle all summer becomes seized due to internal corrosion or settled sludge.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like D.10 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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