BoilerFaultCodesYour boiler has detected an electrical wiring error where the power supply wires are likely swapped or there is a serious grounding issue.
Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now — this fault can be dangerous if ignored.
Technical description: Simultaneous Reversed Polarity
What causes this fault?
This fault occurs when the electrical supply to the boiler is wired incorrectly, specifically if the live and neutral wires have been swapped. It can also be triggered by a faulty earth connection or a failing circuit board that can no longer correctly sense the incoming power. This often happens following recent electrical work in the home or if a component has suffered a significant internal short circuit.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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