BoilerFaultCodesTechnical 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.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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