BoilerFaultCodesTechnical description
Control box failure
What causes this fault?
This fault occurs when the boiler's main electronic circuit board suffers a hardware failure or a memory error, preventing it from processing safety data. It is often caused by long-term heat exposure degrading the electrical components or a sudden power surge that damages the sensitive microprocessors. Effectively, the boiler can no longer trust its own internal instructions and shuts down to prevent an accident.
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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