Why does my electrical panel smell like burning plastic?

What Does a Burning Plastic Smell from My Consumer Unit Mean? A burning or acrid plastic smell coming from your consumer unit (fuse box) is one of the clearest warning signs of a potentially dangerous electrical fault. It should never be dismissed as 'just a smell' — it means something inside is getting hot enough to melt or scorch insulation. Most Common Causes Loose connections — A terminal that has worked loose over time causes arcing, which generates intense localised heat Overloaded circuit — Too many high-draw appliances on one circuit causes the wiring or breaker to overheat Failing MCB or RCD — Breakers can degrade internally and overheat without tripping Melting insulation on cables — Often caused by sustained overload or rodent damage Deteriorated wiring — Older rubber or lead-sheathed wiring is especially vulnerable to heat damage What You Should Do Right Now 1. Sniff carefully — Is the smell faint and occasional, or strong and persistent? 2. Look without touching — Check for any visible scorch marks, discolouration, or melted plastic around the panel cover 3. Feel the panel cover — If it is warm or hot to the touch, that is a serious sign 4. Check for tripped breakers — A repeatedly tripping MCB on one circuit can indicate an overload causing heat 5. Do NOT open the consumer unit yourself — Live busbars inside can cause fatal electric shock When to Act Immediately Call 999 or your DNO emergency line if: You see smoke or flames The smell is very strong or getting worse The panel cover is hot You hear crackling or buzzing Call a registered electrician today if: The smell is faint but persistent You notice any discolouration around sockets or switches on affected circuits Your breakers have been tripping frequently A qualified electrician (look for NICEIC or NAPIT registration) can carry out a full inspection and insulation resistance testing to identify the exact source. Do not delay — electrical fires can develop rapidly inside wall cavities where they are invisible until serious damage has occurred.