BoilerFaultCodesTechnical description
Upper water pressure (>2.7b)
What causes this fault?
This fault occurs when the water pressure inside your heating system exceeds safe operating limits, often because the filling loop was left open or has started to leak water back into the system. It can also happen if the internal expansion vessel, which manages pressure changes as water heats up, has lost its air charge or failed. Effectively, there is too much water or not enough room for it to expand, forcing the boiler to shut down for safety.
This fault is frequently seen in autumn when homeowners top up their boiler pressure after a summer of inactivity and accidentally overfill the system.
DIY fix possible
Check that the filling loop valves are fully closedBleed water from a radiator using a bleed key to reduce pressureMonitor the pressure gauge until it returns to between 1.0 and 1.5 barOnce pressure is lowered, press the reset button