Why is my socket getting dangerously hot when charging my phone overnight?
Quick answer
A socket that gets dangerously hot during overnight phone charging is most commonly caused by a loose or corroded terminal connection inside the socket itself. Even low phone charger currents can generate significant heat across a poor connection. Stop using that socket immediately, switch off the circuit at the consumer unit, and do not use the socket again until a qualified electrician has inspected and tested it. A hot socket is a genuine fire risk and should never be ignored.
🏠Homeowner view
Finding a hot socket is understandably alarming, and you are right to take it seriously. While phone chargers draw very little current compared to something like a kettle or washing machine, a socket in poor condition can overheat even under that small load. Here is what is likely happening and what you should do.
Why it gets hot
The most common reason is a loose terminal connection inside the socket faceplate. Over years of use, the screws that clamp the wires inside a socket can loosen slightly. When current passes through a loose joint, resistance increases and that resistance turns into heat. The problem is worst during long continuous use, which is exactly what overnight charging provides.
Other causes worth knowing about include corroded terminals, an overloaded extension lead plugged into that socket, a faulty charger or charging cable, or in older homes, deteriorated wiring behind the socket. Occasionally the socket itself has simply worn out internally, especially if it is more than 25 years old.
What you should do right now
1. Unplug the charger immediately.
2. Switch off that socket at the consumer unit if you know which breaker controls it.
3. Do not use the socket again until it has been checked.
4. Feel carefully around the socket faceplate for any scorch marks, discolouration, or a burning smell, but do not remove the faceplate yourself.
What you should not do
Do not attempt to open the socket yourself, even if you feel confident doing so. Behind that faceplate you will find live conductors, and without the correct tools and knowledge you could receive a fatal electric shock. This is not a job for a YouTube tutorial.
When to call an electrician
You should call a qualified electrician as soon as possible, ideally the same day. Explain that the socket has been getting hot during overnight charging. Any competent electrician will inspect the wiring, tighten or replace terminals, check the condition of the cable behind the socket, and test the circuit before confirming it is safe to use. If there is any sign of scorching or melted plastic, treat it as an emergency.