A drink preparing machine that includes a tank, a water supply system having at least a section for heated water and a section for unheated water, a pump for conveying water from the tank through the supply system as far as a module for preparing the drink, and a valve device arranged so as to control the selective opening and closing of the supply system sections. The valve device is a peristaltic system that includes a compression member for compressing a tube of each supply system section and acting under the effect of an elastic return member.