Heating control method of a multi-drum washing machine

A heating control method of a multi-drum washing machine, the washing machine including a first washing drum provided with a first heater and a second washing drum provided with a second heater, the method comprising:

• before the first washing drum performs a heating process, determining whether or not the second washing drum is performing a heating process, if the second washing drum is not performing the heating process, the first washing drum performs the heating process, if the second washing drum is performing the heating process, determining whether or not a remaining heating time of the second washing drum is smaller than a set value Tmin,
• if the remaining heating time of the second washing drum is smaller than the set value Tmin, the first washing drum suspends performing the heating process, and the first washing drum does not perform the heating process until the heating process of the second washing drum is completed, if the remaining heating time of the second washing drum is larger than or equal to the set value Tmin, it is compared between a remaining heating time of the first washing drum and the remaining heating time of the second washing drum, the washing drum having a shorter remaining heating time preferentially performs the heating process, and the other washing drum is followed to perform the heating process;
• when the remaining heating time of the first washing drum and the second washing drum are equal, determining whether or not the remaining heating time of the washing drums is greater than a set value Tmax,
• if the remaining heating time of the washing drums is greater than the set value Tmax, an alternate heating process for alternately heating the first washing drum and the second washing drum is performed,
• if the remaining heating time of the washing drums is smaller than or equal to the set value Tmax, a sequential heating process, in which the second washing drum heats first, then the first washing drum heats, is performed.