Lexington Volunteer Fire Department was called to a small apartment complex just west of the downtown Lexington area around 11:20am Wednesday. Fire Chief Dahlas Holbein says they encountered heavy smoke coming from a building at Water Tower Court. The building has a residential area on one side and an office for the apartments on the other side. Firefighters made entry on the residential side and using a camera, found a hot area in the floor. It was later determined that the fire started on the residential side in a furnace that had a rug over it. A similar system is used on the other side of the wall in the office and when the office system was turned on, it turned the residential furnace on as well. The fire burned through the floor and affected some joists. No one was injured.