BoilerFaultCodesYour boiler has lost water pressure, which prevents it from firing up to provide heating or hot water.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Boiler has a fault for a specific error.
What causes this fault?
This fault occurs when the water pressure inside your heating system drops below a safe operating level, causing the boiler to shut down to prevent damage. The most common reasons for this are a leak somewhere in your radiator network or the pressure naturally dropping over time, especially after you have bled your radiators.
This fault is more common in autumn and winter when homeowners turn their heating back on after a long break and notice leaks from valves or joints.
DIY fix possible
Locate the filling loop (braided flexible hose) underneath the boiler.Slowly open the one or two blue-handled valves until you hear water flowing.Close the valves tightly once the pressure gauge needle reaches between 1 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 F01 — 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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