BoilerFaultCodesYour boiler has detected that the water pressure in the system is too low to operate safely and has shut down to prevent damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Low water pressure
What causes this fault?
This fault occurs when the internal sensors detect that there isn't enough water circulating within your heating system to safely transfer heat. The most common reasons are a slow leak from a radiator valve or pipework, or the air pressure in your expansion vessel needing to be recharged.
This code is particularly common in autumn when homeowners turn their heating back on for the first time, as cold systems often drop in pressure over a long summer of inactivity.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.Slowly open the one or two taps/valves on the filling loop until you hear water flowing.Watch the pressure gauge and close the taps firmly when the needle reaches between 1.0 and 1.5 bar.Restart the boiler if it does not reset automatically.
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A boiler cover plan would cover faults like F37 — 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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