BoilerFaultCodesTechnical description
High water pressure error
What causes this fault?
This fault occurs when the water pressure inside your boiler exceeds a safe limit, usually because the heating system has been overfilled via the manual filling loop. It can also be caused by a faulty tap on that filling loop leaking water into the system or an internal failure of the expansion vessel which normally helps manage pressure changes.
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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