BoilerFaultCodesYour boiler has stopped working because the water pressure is too low and needs to be topped up.
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 Switch Not Operated
What causes this fault?
This fault occurs when the water pressure inside your central heating system drops below the minimum level required for the boiler to operate safely. The most common reason is a tiny leak in the pipework or radiators, though it can also happen if you have recently bled your radiators and haven't topped the pressure back up.
This fault is frequently seen at the start of autumn when homeowners turn their heating back on after the summer and find the system has naturally lost pressure over time.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath your boiler.Slowly open the one or two taps/valves until you hear water entering the system.Watch the pressure gauge and close the taps once the needle reaches between 1 and 1.5 bar.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like E119 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Potterton Gold HE is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
Affiliate links — we may earn a commission at no extra cost to you.