BoilerFaultCodesTechnical description
System water pressure high – try bleeding water from your radiators
What causes this fault?
This fault occurs when the internal water pressure exceeds the safe operating limit, often because the manual filling loop has been left slightly open or the expansion vessel has lost its air charge. When the water in your heating system heats up, it expands; if there is nowhere for this extra volume to go or if the system is overfilled, the pressure rises too high and triggers a safety shutdown.
DIY fix possible
Check that the filling loop taps are fully closedSwitch off the boiler and allow the system to coolBleed water from a radiator using a bleed key into a containerMonitor the pressure gauge until it returns to between 1.0 and 1.5 bar
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