Technical description
No communication.
What causes this fault?
This fault occurs when the boiler's main control board loses its ability to 'talk' to the internal sensors or the display screen. The most common reason is a loose connection or a degraded wire within the internal harness, though it can also be caused by the electronic control board failing entirely. Because the boiler can no longer monitor its own safety sensors, it shuts down immediately to prevent damage.
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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