BoilerFaultCodesTechnical description
Controller - Non-volatile lockout
What causes this fault?
This fault occurs when the boiler's internal memory experiences a hardware failure, meaning it can no longer store or retrieve the vital settings needed to run safely. It is usually caused by wear and tear on the electrical components or a sudden power surge that has corrupted the main control board. Because the boiler can no longer trust its own safety instructions, it locks down permanently to prevent any operational risks.
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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