Styrningsmetod för en avfrostningsvärmare för en luftkonditioneringsapparat

Provided is a defrost heater control method for an air conditioner, whereby an antifreezing defrost heater provided on an outdoor unit base can be appropriately controlled to prevent a wasteful power consumption and to reliably prevent drain water from freezing again. In the defrost heater control method for an air conditioner, the antifreezing defrost heater is placed on the outdoor unit base, and is energized under the defrost conditions, to prevent drain water from freezing. The defrost heater control method is characterized in that the defrost heater is energized when the outside air temperature (ThO-A) and the outdoor heat exchanger temperature (ThO-R) are respectively not more than a predetermined temperature, and the difference between the outside air temperature (ThO-A) and the outdoor heat exchanger temperature (ThO-R) is not less than a predetermined value (A) determined in accordance with the outside air temperature (ThO-A), and is heated so as to have a constant temperature.