Disclosed is a method of controlling a real-time oxidation-reduction potential in a hot water system to inhibit corrosion in the hot water system. The method includes defining one or more operational protective zones in the hot water system. One or more of the operational protective zones includes an oxidation-reduction potential probe that is operable to measure a real-time oxidation-reduction potential in the hot water system at operating temperature and pressure. The probe transmits the measured real-time potential to the controller, which assesses and interprets the transmitted potential to determine whether it conforms to an oxidation-reduction potential setting. If the measured potential does not conform the oxidation-reduction potential setting, the controller is operable to feed one or more active chemical species into the hot water system.