High Lockout
EP on Ideal Maximiser SE

Your boiler's internal computer parts are unable to talk to each other correctly because they are not compatible.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Control panel and BIM not compatible.

What causes this fault?

This fault occurs when the main control board and the interface module inside the boiler are unable to communicate because they do not recognise each other's software versions. The most common reason is that a replacement part has been installed that is not the correct match for the specific model, or a internal electronic failure has caused the components to lose their configuration.

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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