A sanitary warm water system, comprising a warm water recirculation system with: - a water annular duct, - a pump connected with the annular duct in a pumping point to circulate water in the annular duct, - heating means connected with the annular duct in a heating point and configured to heat the water during the passage thereof through the heating point, - one or more withdrawing ducts connected with the annular duct at respective withdrawing points, - a supplying duct connected with the annular duct in a supplying point, wherein the sanitary water system further comprises a disinfection system having: - an electronic control system, - a monochloramine generator in signal connection with the control system and connected with the annular duct in a disinfectant insertion point, wherein the generator is configured to synthesize monochloramine and to add the synthesized monochloramine to the warm water or is configured to directly synthesize monochloramine in the warm water in the disinfectant insertion point, - a ammonium ion abatement device in signal connection with the control system and connected with the annular duct in an abatement point, wherein the abatement device is configured to add chlorine or hypochlorites to the water at the abatement point, - ammonium detecting means in signal connection with the control system and connected with the annular duct at an ammonium detecting point, the ammonium detecting means being configured to detect a quantity representative of the ammonium ion concentration in the warm water at the ammonium detecting point, and to transmit a corresponding ammonium concentration signal to the control system, wherein the control system: - activates the monochloramine generator and controls the monochloramine synthesis and addition, and - activates the ammonium ion abatement device and controls the chlorine or hypochlorite addition as a function of the ammonium concentration signals, independently from the monochloramine generator activation. - a water annular duct, - a pump connected with the annular duct in a pumping point to circulate water in the annular duct, - heating means connected with the annular duct in a heating point and configured to heat the water during the passage thereof through the heating point, - one or more withdrawing ducts connected with the annular duct at respective withdrawing points, - a supplying duct connected with the annular duct in a supplying point, - an electronic control system, - a monochloramine generator in signal connection with the control system and connected with the annular duct in a disinfectant insertion point, wherein the generator is configured to synthesize monochloramine and to add the synthesized monochloramine to the warm water or is configured to directly synthesize monochloramine in the warm water in the disinfectant insertion point, - a ammonium ion abatement device in signal connection with the control system and connected with the annular duct in an abatement point, wherein the abatement device is configured to add chlorine or hypochlorites to the water at the abatement point, - ammonium detecting means in signal connection with the control system and connected with the annular duct at an ammonium detecting point, the ammonium detecting means being configured to detect a quantity representative of the ammonium ion concentration in the warm water at the ammonium detecting point, and to transmit a corresponding ammonium concentration signal to the control system, - activates the monochloramine generator and controls the monochloramine synthesis and addition, and - activates the ammonium ion abatement device and controls the chlorine or hypochlorite addition as a function of the ammonium concentration signals, independently from the monochloramine generator activation.