BoilerFaultCodesYour boiler is struggling to move water around the system before it starts the ignition process, which is preventing it from firing up.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Pre-circulation 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 just before the burner ignites. The most common reason is a failing or seized circulation pump, though it can also be triggered by a build-up of sludge or debris blocking the pathways within the heat exchanger.
This fault is frequently seen in autumn when the heating is turned back on for the first time, as pump components can seize up after being idle throughout the summer.
DIY fix possible
Check that the boiler pressure is between 1.0 and 1.5 bar on the gaugeIf pressure is low, use the filling loop to top it upEnsure all radiator valves and isolation valves under the boiler are fully openRestart the boiler using the reset button
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A boiler cover plan would cover faults like E109 — 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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