High Lockout
14 on Glow-worm EnergySaver Combi

Your boiler’s main computer brain has developed an internal electrical error and has stopped the unit from working for safety.

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

There is an internal fault in the Automatic Control Module.

What causes this fault?

This fault occurs when the boiler's main control board experiences an internal hardware failure, meaning the electronic components can no longer talk to each other correctly. The most common reason is historical heat stress or a power surge that has damaged the delicate circuitry inside the module, causing it to shut down for safety.

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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