High Lockout
20 on Glow-worm Ci Range

Your boiler's internal control screen is unable to communicate properly with the main computer board, often after a recent repair or parts change.

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

User interface not compatible with boiler

What causes this fault?

This fault occurs when the boiler's internal display panel and the main control board are unable to understand each other's signals. It most commonly happens after a recent repair where a new part has been installed that isn't programmed correctly or is mismatched for your specific model. Essentially, the boiler’s 'brain' and 'face' are no longer speaking the same language.

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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