Four fire engines and around 25 firefighters were called to a fire at a shop just off Eden Street in Kingston Upon Thames.
A small part of the basement below a shop was damaged by fire. There were no reports of any injuries.
The Brigade’s Fire Investigators believe the fire was caused by an electrical fault within a kettle.
A London Fire Brigade spokesperson said: "Make sure that you turn off and unplug electrical appliances when you've finished using them unless they are designed to be left on, like your fridge or freezer.
"It’s also a good idea to register any appliances that you buy, especially white goods, as you’ll be informed if any issues with the product are identified."
The Brigade was called at 0944 and the fire was under control at 1128. Fire crews from Kingston, Surbiton and New Malden fire stations attended the scene.