BoilerFaultCodesTechnical description
Mains power fault – electrical power interruption
What causes this fault?
This fault occurs when the boiler's main control board detects a sudden loss or interruption in the electrical supply. It is often triggered by a localized power cut, a blown fuse within the unit, or a loose internal wiring connection that breaks the circuit. In some cases, a failing electronic component on the main circuit board can no longer process the incoming power correctly.
This fault is slightly more common during the winter months when storms and high winds are more likely to cause external power surges or brief grid outages.
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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