BoilerFaultCodesYour boiler has stopped working because the water pressure 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: Lack of water fault (<0.5b)
What causes this fault?
This fault occurs when the system loses the water pressure required to circulate heat around your home safely. The most common reason is a slow leak from a radiator valve or joint, though the pressure can also drop if you have recently bled your radiators without topping the water back up.
This issue is more frequent during autumn and winter when the heating is first turned on, as the increased pressure of a hot system can expose small leaks or weak seals.
DIY fix possible
Locate the filling loop (the flexible silver hose) underneath or near the boiler.Slowly open the one or two small taps on the hose until you hear water flowing.Watch the pressure gauge and close the taps firmly when the needle reaches 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 0.5bar — no call-out fees, no surprises.
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Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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