BoilerFaultCodesTechnical description
Supply L and N are reversed
What causes this fault?
This fault occurs when the live and neutral electrical connections are swapped, meaning the power is flowing into the boiler through the wrong wire. It typically happens after recent electrical work has been carried out near the boiler, or if a new fused spur was installed incorrectly. Because this is a safety risk, the boiler's control board will automatically stop the unit from firing until the wiring is corrected.
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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