BoilerFaultCodesYour boiler has detected that the water pressure inside the system is too low and has switched itself off as a safety precaution.
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 in the primary circuit
What causes this fault?
This fault occurs when the water level inside your central heating system drops below a safe threshold, leaving the boiler unable to circulate heat. The most common reasons are a slow leak from a radiator valve or pipework, or the air being let out of the system during recent maintenance or bleeding of radiators.
This issue is frequently seen in autumn when homeowners turn their heating back on for the first time, as the change in temperature can highlight minor leaks or pressure drops developed over the summer.
DIY fix possible
Locate the filling loop (the flexible silver hose) underneath or near the boilerSlowly open the one or two taps/valves until you hear water enteringWatch the pressure gauge until it reaches between 1 and 1.5 bar, then close the valves tightly
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 24 — 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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