Patent ID: 8152932

Claim:
A method for removing scum in a tub of an electronically controlled drum washing machine, the method comprising: alternately rotating a drum following a main washing cycle and pumping liquid out of the drum; pumping a liquid out of the drum for between 30 seconds to 15 minutes following the main washing cycle and pumping liquid out of the drum; regulating a level of water following the main washing cycle and pumping liquid out of the drum by: introducing a quantity of water into the drum which is sufficient to cover all water channels based on a pressure hysteresis measured by a pressure sensor used to determine a level of liquid in the tub such that a scum dilution results without renewed scum formation; and rinsing over a short period of time t 2 , wherein the short period of time t 2 includes a range of 1 minute to 5 minutes; and pumping liquid out of the drum while the drum is moved at a low rotational speed following the main washing cycle and pumping liquid out of the drum, wherein the low rotational speed includes a range of 20 to 60 revolutions per minute, wherein the electronically controlled drum washing machine includes a detergent-solution runoff system arranged on the base of the tub which has a detergent-solution pump and the pressure sensor for determining the level of liquid contained in the tub, the signal from this pressure sensor being recorded during operation of the detergent-solution pump, and the drum.