BoilerFaultCodesTechnical description
Water pressure too high. The system pressure is too high.
What causes this fault?
This fault occurs when the water pressure inside your heating system exceeds the safe limit, often because the filling loop used to top up the system has been left slightly open or is leaking. It can also happen if the expansion vessel, which manages heat-related pressure changes, has failed or if the system has been significantly overfilled during recent maintenance.
This fault is more common in autumn when homeowners top up their system pressure ahead of the heating season and accidentally add too much water.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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