BoilerFaultCodesYour boiler has switched itself off 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: The filling pressure falls below 0.05 MPa (0.5 bar) and the product switches off.
What causes this fault?
This fault occurs when the water pressure inside your heating system drops below a safe working level, causing the boiler to shut down to prevent internal damage. The most common reason is a slow leak from a radiator valve or pipework, though it can also happen if you have recently bled your radiators and haven't topped the pressure back up.
This code is frequently seen at the start of autumn when homeowners turn their heating back on for the first time after summer, revealing pressure losses that occurred while the system was idle.
DIY fix possible
Locate the filling loop (usually two silver braided hoses) underneath the boilerSlowly open both taps on the filling loop until you hear water movingClose both taps tightly once the pressure gauge on the screen reaches 1.5 bar
Find a Gas Safe engineer
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Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like F.22 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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