BoilerFaultCodesYour boiler has detected that the water pressure is too low to operate safely and has temporarily stopped working.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Water pressure test
What causes this fault?
This fault occurs when the system's internal sensors detect that the water pressure has dropped below the minimum level required to heat your home safely. The most common reason is a minor leak in the pipework or radiators, or it could simply be that air was recently bled from your radiators, leaving the system under-filled.
This fault often appears in autumn when homeowners turn their heating back on for the first time after summer, revealing pressure drops that occurred while the system was dormant.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath your boiler.Open the small valves on the hose slowly until you hear water entering the system.Watch the pressure gauge and close the valves once the needle reaches between 1.0 and 1.5 bar.
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A boiler cover plan would cover faults like E430 — 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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