A machine cleaner tablet comprising from about 10 to about 75% of a limescale remover acid, from about 1 to about 20% of low foaming non-ionic surfactant, from about 0.5 to about 5% of a detergency enzyme and wherein the tablet has a pH measured as a 1% solution in distilled water at 20.degree. C. in the range from about 1 to about 5. The tablet is used for cleaning the interior of automatic dishwashers, food processing machines and the like.