Dishwasher

A control method for a dishwasher comprising a spray arm configured to spray washing water to a washing object, a sump configured to provide a space where washing water is stored and to collect washing water sprayed from the spray arm, a housing configured to connect the sump and the spray arm, a heater located in the housing, an impeller located in the housing and above the heater, and a motor configured to rotate the impeller, the control method comprising:

• supplying washing water to the sump;
• rotating the impeller by supplying electricity to the motor;
• during a preset reference time period after beginning to rotate the impeller by supplying electricity to the motor, measuring an amount of electric current supplied to the motor during the rotating of the impeller;
• and
• heating washing water located in the housing by operating the heater based on the amount of electric current supplied to the motor during the rotating of the impeller being greater than or equal to a preset reference amount.