Burning smell, sparking or hot sockets

If you see smoke or flames, get everyone out, close the door behind you and call 999. Do not try to put out an electrical fire with water.

If there is no fire, switch off the appliance at the wall and unplug it if the plug is not hot. Then switch off the circuit at the consumer unit, or the main switch if you are not sure which circuit it is. Do not use the socket again until it has been checked. Keep children and pets away.

If the smell is coming from the consumer unit itself, switch off the main switch only if you can reach it without touching anything that is hot or damaged, then call for help.

Heat at a socket almost always comes from a poor connection or too much load. A terminal screw that has worked loose creates resistance, and resistance makes heat. Over time the plastic browns, then chars. Plug tops can do the same if the fuse is loose or the pins are worn.

Load is the other cause. A double socket running a fan heater and a tumble dryer through an extension lead can carry more than it was meant to for hours. The London Fire Brigade lists hot plugs and sockets and scorch marks among the warning signs of loose or dangerous wiring, and says it has attended 26,376 electrical fires in London since 2017.

In flats and older houses there are often fewer sockets than people need, so extension leads stack up. In homes where black rubber cable survives, which Electrical Safety First says was phased out in the 1960s, heat at a socket can damage insulation that is already brittle.

The electrician will check the cable behind the socket, not only the faceplate, because heat travels along copper. If the cable insulation has hardened or cracked, it gets cut back to sound cable or replaced. If the root cause is too few sockets, adding sockets or a new circuit is usually the real fix.

A smell of burning from the consumer unit itself is more serious than one from a socket, because every circuit in the home starts there. Common causes are a loose connection on a breaker or the main switch, or overheated meter tails where they enter the board.

If you can reach the main switch without touching anything that looks scorched or feels hot, switch it off. If the smell is near the meter or the sealed box next to it, that equipment belongs to the network operator and the supplier, so call 105 as well as an electrician. Do not open the board or the meter cupboard seals.

Older plastic boards, often found in flats wired in the 1990s and 2000s, can show heat damage on the case. New boards in homes are made with a non combustible enclosure, which in practice means metal. Our advice on a burning smell from the fuse box goes through the steps in order.