BoilerFaultCodesYour boiler has stopped working because water is not moving through the system properly or the pressure is too low.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: water flow fault
What causes this fault?
This fault occurs when the boiler's internal sensors detect that water isn't moving through the unit quickly enough to safely carry heat away from the burner. The most common reasons are a failed internal pump, a build-up of debris causing a blockage in the pipework, or air trapped within the system. It can also be triggered if the system pressure has dropped too low for the pump to operate effectively.
This issue often surfaces during the first cold spell of autumn when the heating is turned on after being idle all summer, which can cause the internal pump to seize.
DIY fix possible
Check that the boiler pressure gauge is between 1 and 1.5 barIf the pressure is low, use the filling loop to top it upEnsure all radiator valves and boiler isolation valves are fully openReset the boiler once the pressure is corrected
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A boiler cover plan would cover faults like E8 — 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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