BoilerFaultCodesYour boiler has detected that there is not enough water in the system to operate safely, causing it to shut down to prevent damage.
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
What causes this fault?
This fault occurs when the internal sensors detect that the water pressure has dropped below a safe level for the pump and heat exchanger to function. The most common reasons are a slow leak hidden somewhere in your pipework or radiators, or because you recently bled your radiators without topping the system back up.
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 small leaks or pressure losses that occurred over the summer.
DIY fix possible
Locate the filling loop valves on the pipework underneath the boiler.Slowly open the valves 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 4.11 — 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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