Technical description
No mains voltage to the boiler, blown EMC filter, or external fault.
What causes this fault?
This fault occurs when the electrical supply to the boiler is interrupted or fails to reach the internal control system. The most common reason is a blown fuse or a failed component like the EMC filter that has blocked the incoming power to prevent further electrical damage. It can also be caused by an external issue, such as a tripped circuit breaker in your home's main fuse box.
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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