BoilerFaultCodesYour boiler has switched itself off because the water pressure in the system has dropped 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: Safety switch-off: Low water pressure
What causes this fault?
This fault occurs when the internal sensors detect that there isn't enough water circulating through the boiler to operate safely. The most common reasons are a slow leak somewhere in your radiator network or air being released from the system, both of which cause the pressure to bottom out.
This issue is frequently seen in autumn when homeowners turn their heating back on for the first time after summer, as dormant leaks or trapped air become apparent.
DIY fix possible
Locate the filling loop (usually a silver braided hose with two small valves) underneath the boiler.Slowly open both valves until you hear water flowing and watch the pressure gauge.Close both valves tightly once the pressure reaches between 1.0 and 1.5 bar.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like F.22 — 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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