Any portable electrical appliances require occasional check-ups in order to make sure that they are safe to use. This is called Portable Appliance Testing, or PAT, and this is vital to the to the safety of your property.
If your portable electrical device is damaged in any way then it may be unable to carry the voltage required to run the appliance. This is not only a problem due to the device possibly breaking, but also the chance of it starting a fire. It is therefore highly important that all PAT tests are carried out by a fully qualified professional electrician as they have the experience and the knowledge to correctly check the device, and make sure that it is safe to use.
All of your electrical appliances should be inspected and PAT tested at least once per year, in order to make sure that they are up to standard by a professional electrician in London.