Four fire engines and around 25 firefighters tackled a fire at a flat on Staines Road in Hounslow.
Part of a flat on the first floor and part of the roof of a mixed-use two-storey building was damaged by fire. There were no reports of any injuries.
The fire is being treated as accidental and is believed to have involved a fridge freezer.
A London Fire Brigade spokesperson said: "It’s important to make sure you’re aware of white goods safety and to check your appliances.
"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.
"You should also always keep your white goods in a safe place out of the way as if a fire does break out you will need clear escape routes."
The Brigade's 999 Control Officers received five calls about the fire.
The Brigade was called at 1648 and the fire was under control by 1815. Crews from Feltham, Heathrow, Chiswick and North Kensington fire stations attended the scene.