BoilerFaultCodesYour boiler has detected that the water pressure is too low for it to operate safely and has shut down.
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 system water pressure drops below the minimum level required for the boiler to heat up safely. The most common reason is a small leak in the radiator network or pipework, but it can also happen if you have recently bled your radiators without topping the water back up. When the internal sensor detects this lack of pressure, it cuts the power to the burner to prevent the unit from overheating.
This issue often occurs at the start of autumn when homeowners turn their heating back on for the first time or bleed their radiators to remove air pockets.
DIY fix possible
Locate the filling loop (a flexible silver hose) underneath or near the boilerSlowly open the one or two taps/levers on the filling loop until you hear water movingWatch the pressure gauge and close the taps when the needle reaches 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.
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Potterton Promax Combi HE Plus 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.
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