Four fire engines and 21 firefighters and officers were called to a fire at a shop with flats above in Tottenham Court Road.
Four air conditioning units at first floor roof level were damaged by fire.
The Brigade was called at 1515 and the fire was under control at 1609. Fire crews from Euston, Soho and Islington fire stations attended the scene.
The cause of the fire is accidental and believed to have started in the electrical side of an air conditioning unit.