Why does my electrical panel smell like burning plastic when turned on?

A burning plastic smell coming from your consumer unit or fuse box is not something to dismiss as minor. It is one of the clearest warning signs that something inside your electrical panel is overheating, and in the worst cases it means a fire could already be starting inside the wall or within the unit itself. What is likely causing it The most common reasons for this smell include a circuit breaker or fuse that is overloaded and running too hot, a loose wire connection that is arcing and burning the surrounding insulation, an old or failing consumer unit with components that are beginning to break down, or a wiring fault that is drawing more current than the cables can safely carry. What you should do right now Do not open the consumer unit yourself. The inside of a live consumer unit contains potentially lethal voltages. Turn off your main switch at the consumer unit if you can do so safely without touching any exposed parts. Do not use any circuits or sockets in your home until the fault has been found and fixed. If the smell is strong, you see scorch marks, smoke, or discolouration around the panel, treat it as a fire emergency and call 999 first. Ventilate the area by opening windows if it is safe to do so. Call a registered electrician immediately, ideally one registered with NICEIC, NAPIT, or a similar scheme. Explain that you have a burning smell from your consumer unit so they understand the urgency. When did the smell start If the smell started when you first switched on a new appliance, that particular circuit may be overloaded. If it appeared gradually over time, it is more likely to be a deteriorating connection or ageing equipment. Either way, an electrician needs to investigate. Older homes with rewirable fuse boxes or split-load consumer units from the 1980s and 1990s are particularly at risk, as the components have often exceeded their designed service life. A full inspection and possible replacement of the consumer unit may be recommended. Do not wait to see if it gets worse. A burning smell from an electrical panel is always treated as a potential emergency.