High Lockout
235 on Worcester Bosch GB162

Your boiler’s internal control parts are speaking different languages because a newer component has been installed that is incompatible with the older system.

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

The KIM (boiler identification module) is too new for the burner control unit

What causes this fault?

This fault occurs when a replacement part is installed that uses a newer software version than the boiler's main brain can understand. It is almost always triggered following a recent repair where a new KIM identification module or burner control unit was fitted without checking their version compatibility. Essentially, the boiler has been given a component that is too modern for the rest of its internal system to work with.

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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