BoilerFaultCodesYour boiler has stopped working because the water pressure in the central heating system has dropped too low.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: CH system pressure less than 0.5 bar / water pressure switch fault
What causes this fault?
This fault occurs when the internal sensor detects that the water pressure has dropped below the minimum level required for the boiler to operate safely. The most common reason is a slow leak somewhere in your radiators or pipework, or simply that the expansion vessel needs recharging. Without enough water pressure, the boiler cannot circulate heat effectively and will shut down to prevent internal damage.
This fault is frequently seen in autumn when the heating is turned on for the first time after summer, as air can trapped in radiators and settled leaks become apparent.
DIY fix possible
Locate the internal or external filling loop (flexible silver hose) under the boiler.Slowly open the valve(s) to allow water into the system while watching the pressure gauge.Close the valves firmly once the needle reaches between 1.0 and 1.5 bar.
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A boiler cover plan would cover faults like 119 — no call-out fees, no surprises.
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