Why does my socket smell of burning plastic when the microwave runs?

Why Your Socket Smells of Burning Plastic When the Microwave Runs That burning plastic smell is your home's wiring telling you something is seriously wrong. It is not a minor inconvenience — it is an early warning sign of a potential electrical fire. What Is Most Likely Happening Microwaves draw a large current, typically between 6 and 13 amps, every time they run. If there is any weakness in the socket's connections, that high current causes the metal terminals to heat up, arc, and char the surrounding plastic. The smell you notice is literally the socket housing beginning to melt or burn. Common causes include: Loose terminal screws inside the socket — the most frequent cause Backstab (push-in) connections that have worked loose over time A socket that was undersized, damaged, or poorly installed originally Old or corroded wiring that makes poor contact with the terminals A socket that has been overloaded with an extension lead previously The socket being partially rated — older 13A sockets can degrade internally What You Should Do Right Now 1. Stop using that socket immediately 2. Unplug the microwave 3. Switch off the circuit at your consumer unit (fuse box) — find the breaker labelled kitchen ring or sockets 4. Do NOT remove the socket faceplate yourself unless you are confident and the circuit is confirmed dead with a voltage tester 5. Call a qualified electrician — look for someone registered with NICEIC, NAPIT, or ELECSA What Not To Do Do not plug the microwave into an extension lead as a workaround Do not assume the smell will go away on its own Do not ignore it and carry on — arcing inside a socket can ignite the wall cavity behind it When Is It an Emergency? If you can see scorch marks, the socket is discoloured brown or black, or you smell burning even when nothing is plugged in, treat it as an emergency. Call an electrician the same day.