BoilerFaultCodesYour boiler's internal computer has lost contact with the main control system, meaning the components cannot talk to each other to start the heating process.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Break in communication
What causes this fault?
This fault occurs when the data link between the boiler's internal computer and the heat exchanger sensors is interrupted. The most common reason is a loose connection or moisture damage on the communication cable, but it can also be caused by a critical electronic failure within the main control board itself.
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 A8 — no call-out fees, no surprises.
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