BoilerFaultCodesYour boiler has stopped working because the water pressure in 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: Insufficient system water pressure
What causes this fault?
This fault occurs when the water pressure inside your heating system drops below the minimum level required for the boiler to fire up safely. The most common reasons are a leak somewhere in your radiator pipework or a faulty expansion vessel that is no longer able to maintain steady pressure as the water heats up.
This issue often appears when you turn your heating back on for the first time in autumn, as the system settles after being idle for several months.
DIY fix possible
Locate the filling loop (a flexible silver hose) underneath or near the boiler.Open the one or two small valves on the loop slowly until you hear water moving.Watch the pressure gauge until it reaches between 1.0 and 1.5 bar, then close the valves tightly.Reset the boiler using the mode selector dial.
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