What is a split neutral fault and can it cause a house fire?

A split neutral fault might sound technical, but the effects in your home can be very noticeable and potentially dangerous. Here is what you need to know in plain language. What the neutral wire actually does In your home's electrical system, every circuit has a live wire that brings power in and a neutral wire that returns it. The neutral wire is just as important as the live. If the neutral is interrupted or develops a high-resistance connection anywhere along its path, things go wrong quickly. What a split neutral actually means A split neutral fault is when the neutral conductor is broken, loose, or has developed a very high resistance at some point. The word split refers to the fault creating two separate sections of the neutral, neither of which is doing its job properly. This is particularly dangerous in a system fed from a three-phase supply, such as in a large property or a flat fed from shared supply cables. What you might notice in your home Some lights flickering or going very bright while others dim down unexpectedly. Appliances behaving strangely, running too fast or too slow. A burning smell near the consumer unit, a socket, or a fuse spur. RCD or breakers tripping for no obvious reason. Bulbs blowing frequently in one part of the house. Can it cause a fire? Yes, absolutely. A loose or broken neutral causes arcing at the fault point, and arcing generates intense heat that can ignite surrounding materials including cable insulation, plastic enclosures, and timber. Appliances connected across an unbalanced supply can also overheat internally. This is a serious fire risk. What you should and should not do Do not start removing socket covers or poking around in the consumer unit yourself. Neutral faults can leave metalwork live in unexpected ways, meaning things you expect to be safe to touch may not be. Safely, you can check whether any visible accessories such as sockets or light switches are warm to the touch or discoloured. You can also check whether your symptoms match, for example lights getting brighter or dimmer when another appliance switches on. If you notice any of these signs, turn off the main switch at your consumer unit and call a qualified electrician. This is not a fault to leave until the weekend.