High
20 on Glow-worm 18si

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

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.

What the manual says

Manufacturer manual

User interface not compatible with boiler

From this model's manual
Verified against the Glow Worm Ci Range installation & service manual, page 34.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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Avoid the next call-out bill

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