The present invention refers to a machine, such as a washing machine, in particular a dishwashing machine and a clothes washing machine, an ironing machine, a food cooking oven and a boiling pan of the kind intended for use in professional kitchens, such machine being provided with water heating means 6,l 36, 46) and being further provided with a device adapted to curb and reduce scale formation. A machine provided according to the present invention is characterized in that it comprises an electrolytic cell (2, 22, 32, 42) eluting zinc ions in the process water, and in that it further comprises sensor means (11, 211, 211a, 311, 411) and processing means (12, 212, 312, 412) for determining the (Zn)-to-(Ca) ratio, i.e. the ratio of the concentration by weight of zinc to the concentration by weight of calcium in said water.