All Gas Regulators stocks thousands of Rheem comfort replacement parts and accessories. Brothers Richard and Donald Rheem founded Rheem Manufacturing Company in Emeryville, Calif., in 1925. While the company has produced a number of products in its nearly 100 years of operation — including steel shipping containers, household appliances like gas ranges, semi-conductors, musical instruments and more — Rheem today is the only manufacturer in the world that produces heating, cooling, water heating, pool/spa heating and commercial refrigeration products, and it is the largest manufacturer of water heating products in North America.