BoilerFaultCodesYour boiler has detected that the water pressure is too low for it to operate safely, which is usually fixed by topping up the system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Low system water pressure (pressure switch)
What causes this fault?
This fault occurs when the internal sensor detects that there isn't enough water circulating in the system to operate safely. The most common reason is a gradual loss of pressure through tiny leaks or recently bled radiators, though it can also be caused by a faulty sensor or a failing expansion vessel.
This fault is frequently seen at the start of autumn when homeowners turn their heating back on for the first time after summer.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath the boiler.Slowly open the valves until you hear water entering the system.Watch the pressure gauge and close the valves once it reaches 1.5 bar, then restart the boiler.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like E10 — no call-out fees, no surprises.
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Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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