BoilerFaultCodesYour boiler's internal pump is having trouble circulating water through the system, which is preventing your heating from working.
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 internal pump fails to spin or move water effectively through the system. The most common reasons are a mechanical failure of the pump motor, a build-up of debris or 'sludge' blocking the internal components, or a communication issue between the pump and the main control board.
This issue is frequently seen at the start of autumn when heating systems are turned back on after being idle all summer, as pumps can seize up during long periods of inactivity.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like D.10 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
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.
Affiliate links — we may earn a commission at no extra cost to you.