BoilerFaultCodesYour boiler has detected that the water pressure in the system is too low to run safely.
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 closed / low system pressure
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. The most common reason is a small leak somewhere in your radiator system or air being released through a valve, which reduces the overall volume of water. Without enough water pressure, the boiler shuts down to prevent the heat exchanger from overheating or becoming damaged.
This code is often seen in autumn when the heating is turned on for the first time after summer, as pipes and radiators expand and contract, potentially highlighting small leaks or trapped air.
DIY fix possible
Locate the external or internal filling loop (usually silver flexible hoses with blue or black handles).Slowly open the valves until you hear water flowing into the boiler.Monitor the pressure gauge on the front of the boiler until it reaches between 1.0 and 1.5 bar, then close the valves tightly.The boiler should reset automatically, but you may need to press the 'R' or reset button if the code persists.
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