Rheem Tankless Water Heaters

Rheem was founded by brothers Richard S. Rheem and Donald L. Rheem, sons of William S. Rheem, former president of Standard Oil of California. The company began in 1925 manufacturing galvanized steel drums in partnership with Pacific Galvanizing Company. With financing from their brother William K. Rheem, they formally organized Rheem Manufacturing on January 22, 1930, later acquiring Republic Steel’s packaging division, which produced boilers and tanks—marking their entry into water heating.

In 1931, Rheem acquired John Wood Manufacturing Company, expanding into automatic gas storage water heaters, and by 1936 had expanded overseas with a plant in Sydney, Australia. By 1939, the Australian division was producing both drums and water heaters.

By 1941, Rheem had become the largest U.S. manufacturer of automatic water heaters. During World War II, it contributed to shipbuilding and aircraft production. In 1954, Rheem pioneered the glass-lining process, extending water heater lifespan. Two years later, it introduced Rheemaire, its line of central air conditioning and heating systems for homes, solidifying HVAC as a core business. In 1959, Rheem acquired Ruud Manufacturing Company, further strengthening its market position.