High
b... on Keston C90 / C110

Your boiler has detected that it is running too hot or that the pressure in your heating system is too low, so it has purposefully shut down to protect itself from damage.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Overheat or water pressure lockout

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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