Your boiler's control panel has lost communication with the main computer, meaning you cannot adjust settings or operate the unit.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Local user interface fault
What causes this fault?
This fault occurs when the display panel on the front of your boiler can no longer 'talk' to the main internal computer. The most common reason is a loose or damaged connection cable inside the unit, or a components failure on one of the electronic circuit boards. Because the brain of the boiler cannot receive commands from the buttons, the system shuts down as a safety precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like 18 — no call-out fees, no surprises.
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Glow-worm 18si 24ci is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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