BoilerFaultCodesYour boiler has detected that water is not moving through the system properly, which has caused it to stop working for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: No Water Flow
What causes this fault?
This fault occurs when the boiler's internal sensors detect that water isn't circulating through the unit quickly enough to carry heat away safely. The most common reasons include a failing internal pump, a physical blockage in the pipework, or air trapped within the system preventing the flow of water.
This issue is more frequent in autumn when heating systems are turned back on after a summer of inactivity, which can cause the internal pump to seize.
DIY fix possible
Check that your boiler pressure gauge is between 1 and 1.5 barEnsure all radiator valves are fully openVerify that the main stopcock and internal isolation valves are openTurn the power off and back on to reset the system
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 F0 d — 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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