Have specially decided because of Kalkkollektors for this device, as I have very hard water. After about 10 times, use (with Brita-filtered water, according to sales point empfohelen) stopped working the water supply. According to the investigation at the customer service it came back with the remark that the unit had been totally occupied with lime mud. One must after about every 10 times use the Kalkkollektor rinse. Unfortunately, it was nothing at all in the manual! According to the manual you have to rinse the Kalkkollektor if it wishes to display. Am somewhat disappointed and angry. So information should not be missed in the manual! Customer service has "deslimed" to guarantee, but next time I would have to reckon with a bill of up to 150! With so an expensive device that I have bought specially for this Kalkprogrammes I find it not good if I only on the customer service protocol learn important information about the care. So to all buyers: equipment generally good. But please use only decalcified water and rinse after every 10 times Kalkkollektor even if the light is off. In addition, water is not allowed to stand for several days in the tank but most empty after every ironing.