PURPOSE: To improve comfortableness particularly upon heating by driving a fan motor when the difference between the temperature in the vicinity of a ceiling surface and the temperature in the vicinity of the floor surface exceeds a predetermined value.

CONSTITUTION: A room heater 1 is provided on the floor, and a circulator 3 is provided in the vicinity of the ceiling of a wall surface 2. The circulator 3 is provided with a first sensing part 6 which senses the high temperature side in the vicinity of the ceiling surface, a pull switch 4 for manipulation, and an automatic and manual changeover switch 5. A second sensing part 8 for sensing the low temperature side in the vicinity of the floor surface through a lead wire 8 is connected to the circulator 3. When the temperature difference between both sensing parts 6 and 7 exceeds a predetermined value, the fan motor is driven.