BoilerFaultCodesYour boiler has stopped working because either there isn't enough water pressure in the system or the internal pump is unable to circulate water.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fault on Pump or Low System Pressure
What causes this fault?
This fault occurs when the boiler detects that there is not enough water pressure or flow to safely operate the internal heat exchanger. The most common reasons are a simple drop in system pressure that needs topping up, or a mechanical failure of the internal pump which prevents water from moving around your radiators.
This fault often appears when you turn your heating back on for the first time in autumn, as pumps can seize up after sitting idle throughout the summer.
DIY fix possible
Check the pressure gauge on the front of the boiler; if it is below 1 bar, it needs topping up.Locate the filling loop (usually a silver flexible hose) underneath the boiler.Slowly open the valves until the pressure reaches 1.5 bar, then close them tightly.Reset the boiler to see if the fault clears.
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A boiler cover plan would cover faults like 23 — no call-out fees, no surprises.
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