Correct use of extension leads

Extension leads are convenient, but are only intended for occasional use as a temporary solution. Here is our advice on correct use of extension leads.


Check before use

Make sure that the extension lead is intact and undamaged before you use it. Extension leads that are damaged, show signs of wear, or are discoloured should be discarded. Avoid running extension leads from one room to another, or from the house into the garden, as the cable may get pinched or rub on a corner and get damaged. 

Only use child-proof extension leads

Use child-proof extension leads in rooms where children spend time. Child-proof power sockets have internal shutters covering the current-carrying parts that prevent small fingers and other objects from being inserted into the holes.

The shutters often have a contrasting colour so it is easy to see that they are closed. When a plug is inserted into the socket, there is equal pressure on both shutters at the same time and the shutters slide aside so that the plug can be inserted. 

Use the correct length

Use an extension lead that is the right length for the purpose. Do not connect multiple extension leads together. If you use a cable reel, always unwind the cable completely, even if you do not need the full length.

Cables that remained coiled up are more likely to overheat and increase the risk of fire. Avoid dust-gathering tangles of cables behind sofas and other furniture. A thick layer of dust raises the temperature of the cable and in the socket.

Do not overload

Appliances that use a lot of power need special cables that are adapted to the amount of electricity that will pass through them. If you use an extension lead for these kinds of appliances, you may overload the cable. The extension lead will then overheat and could start burning. A good rule of thumb is that appliances that need over 1000 watts should not be run on an extension lead for any length of time. Examples include electric radiators, portable oil heaters, tumble dryers and washing machines. The more electricity an appliance uses, the shorter the time it should be connected via an extension lead.

Upgrade your wiring

If you constantly need to use an extension lead or if they are permanently connected, this means that the wiring is not adequate to meet your needs. Contact an electrician and have more electrical outlets installed. 

Correct use of extension leads:

  • Make sure that the extension lead is intact and undamaged.
  • Make sure the cable is not pinched anywhere.
  • Use a cable that is long enough – avoid cable reels or connecting multiple extension leads.
  • Avoid using an extension lead for high powered appliances.
  • Remember that extension leads are only intended for temporary use.