Washing machine and controlling method therof

A washing machine comprising:

• a tank accommodating water, said tank having a first opening, said tank having a partition to divide a space within said tank into a first space and a second space, said partition having a hole, said first and second spaces communicating with each other through said hole, said first space accommodating an article to be washed;
• a heater mounted in said second space to heat the water in said tank;
• a pump circulating the water from said second space to said first space;
• an input unit mounted on said washing machine to input a washing course, said washing course comprising a cycle of a predetermined suspension time, a predetermined operation time of said pump, and a predetermined water temperature;
• a controller controlling the heater and said pump to adjust a temperature of the water according to the inputted washing course;
• a cabinet accommodating and supporting the tank, said cabinet having a second opening corresponding to said first opening;
• and
• a cover arranged at the upper part of the cabinet, and having at least one pushing projection arranged inside said cover and protruding inward the tank.