Method of controlling washing machine

A method for controlling a washing machine, the washing machine including a tub configured to receive water, a drum having an inlet defined on a front surface thereof and configured to receive laundry, the method comprising:

• supplying a first amount of water to submerge at least a first portion of the drum in the tub;
• performing a first operation for heating water in the tub by a heater while rotating the drum at a first set speed;
• based on performing the first operation, of draining water from the tub;
• based on draining water from the tub, of supplying a second amount of water to submerge at least a second portion of the drum in the tub, the second amount being greater than the first amount;
• and
• based on supplying the second amount of water to the tub, performing a second operation for heating water in the tub by the heater while rotating the drum at a second set speed that is less than the first set speed.