Thermometer Central 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.