Six fire engines and around 40 firefighters were called to a fire in a shop basement in New Cross Road, New Cross.
Part of the basement was damaged by fire. There were no reports of any injuries.
The Brigade's Fire Investigators believe the fire was accidental and involved a fridge.
A London Fire Brigade spokesperson said: “If your white goods start making a strange noise, don’t ignore it. If you think there’s a problem always unplug it and contact the manufacturer or a qualified repair technician.
"Most fires where white goods are the source of ignition are not down to anything you have done – so always make sure you register your appliances as you’ll be informed if any issues are identified with the product you’ve bought."
The Brigade was called at 1427 and the fire was under control by 1550.
Fire crews from New Cross, Old Kent Road, Deptford, Greenwich and surrounding stations were at the scene.