A sanitary warm water system comprises an annular water duct, a pump, a heater, withdrawing ducts connected to the annular duct and a supply duct, a monochloramine generator which synthesizes and adds monochloramine to the warm water in the annular duct at a disinfection point, an ammonium ion abatement device which adds chlorine or hypochlorites to the warm water in the annular duct, an ammonium detector which detects the concentration of ammonium ions in the warm water and a control system which activates the monochloramine generator and activates the ammonium ion abatement device and controls the addition of chlorine or hypochlorite as a function of the ammonium concentration signals, independently of the activation of the monochloramine generator.
