BoilerFaultCodesYour boiler has detected that the water pressure is too low for it to operate safely, or it is struggling to move water through the system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Pressure less than 1 bar or pump pressure increase too low (no pump detection).
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the system lacks the minimum water pressure required to circulate heat safely. The most common reason is a slow leak somewhere in the pipework or radiators, but it can also be triggered if the pump has failed and can no longer push water through the heat exchanger.
This code is frequently seen in autumn when the heating is turned on for the first time after summer, as dormant seals may have weeped or air has become trapped in the radiators.
DIY fix possible
Check the pressure gauge on the front of the boiler; it should ideally be between 1.2 and 1.5 bar.Locate the filling loop (usually a silver braided hose with small black lever valves) underneath the boiler.Slowly open the valves to let water in until the gauge reaches 1.5 bar, then ensure they are closed tightly.Press the Reset button on the control panel to clear the fault.
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