BoilerFaultCodesYour boiler has lost its connection to the main electrical supply or has detected a significant power interruption.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical 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.
DIY fix possible
Check if there is a general power cut in your streetInspect your home's consumer unit (fuse box) to see if a circuit breaker has trippedEnsure the boiler's isolation switch (fused spur) is turned onPress the Reset button on the boiler control panel
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