Method for maintaining set temperature of wash water of clothes washer

A method for maintaining a set temperature of wash water of clothes washer, said method comprising steps of:

• supplying first cold water into a wash tub;
• measuring supply time of said first cold water until the wash tub is filled with the first cold water up to a first target level of said first cold water;
• measuring temperature of said cold water contained in said wash tub;
• supplying hot water and second cold water in said wash tub containing said first cold water;
• measuring supply time of said hot water and said second cold water until the wash tub is filled with said hot water and said second cold water up to a second target level of said hot water and said second cold water;
• measuring temperature of mixed water being comprised of said hot water and said first and second cold water contained in said wash tub;
• and
• comparing temperature of said hot waters which is calculated based on the following four values--supply time of said first cold water, temperature of said first cold water, supply time of said hot water and said second cold water, and temperature of said mixed water--with a predetermined temperature, and controlling a valve for said cold water and a valve for said hot water.