BoilerFaultCodesYour boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
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 pressure sensor detects that there isn't enough water in the system to circulate heat safely. The most common reasons are a slow leak hidden somewhere in your pipework or radiators, or the need to bleed air out of the system after a period of heavy use.
This fault is frequently seen in autumn when homeowners turn their heating back on for the first time, as small leaks or air pockets often develop while the system sits idle over summer.
DIY fix possible
Locate the filling loop (usually two braided silver hoses or blue levers) underneath the boiler.Slowly open both valves until you hear water flowing and the pressure gauge reaches between 1.0 and 1.5 bar.Close both valves tightly and restart the boiler to clear the fault code.
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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