BoilerFaultCodesYour boiler has detected an internal communication error during its self-test phase, which is preventing it from starting up safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Internal check
What causes this fault?
This fault occurs when the boiler's internal computer system fails to complete its startup safety checks. It is usually caused by a breakdown in communication between the electronic components or a failure within the main control board itself. Think of it like a computer failing to load its operating system correctly, which prevents the boiler from firing up for safety reasons.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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