Shoppers and staff at Co-op in Oxted were evacuated this afternoon as smoke filled the shop.
Firefighters from Godstone and Oxted were called to the Station Road East store at 5pm.
The building had already been evacuated.
Firefighters discovered smoke was coming from an electrically-powered water pump in the basement, which had overheated.
Crews isolated the supply and left it for an engineer to fix.
Shoppers were let back into the store within half an hour.
