BoilerFaultCodesYour boiler's internal pump is having trouble moving water through the system, which is preventing it from providing heating or 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: Circulation pump
What causes this fault?
This fault occurs when the boiler's internal pump fails to circulate water effectively through the heat exchanger. The most common reasons are a mechanical failure of the pump motor, a buildup of sludge blocking the internal components, or air trapped within the unit preventing the pump from turning.
This fault is frequent in autumn when heating systems are switched back on after a summer of inactivity, which can cause the pump to seize.
DIY fix possible
Check that your system pressure is between 1.0 and 1.5 bar on the digital displayEnsure all radiator valves and isolation valves under the boiler are fully openBleed your radiators to remove any trapped air that might be blocking water flow
Find a Gas Safe engineer
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Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like T.05 — 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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