BoilerFaultCodesYour boiler has detected that there is not enough water in the system to operate safely, causing it to shut down temporarily.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Water pressure too low
What causes this fault?
This fault occurs when the internal sensors detect that the water pressure has dropped below the minimum level required to circulate heat safely. The most common reason is a small leak somewhere in the central heating pipework or radiators, though it can also happen if you have recently bled your radiators without topping the system back up.
This fault is frequently seen in autumn when homeowners turn their heating back on for the first time, as the system struggles to reach pressure after a long period of inactivity.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath your boiler.Slowly open the one or two taps/valves on the filling loop until you hear water entering the system.Watch the pressure gauge until it reaches between 1.0 and 1.5 bar, then close the taps fully.
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