A.O. Smith is a global leader, applying innovative technologies and energy-efficient solutions to products manufactured and marketed worldwide. The company is one of the world’s leading manufacturers of residential and commercial water heating equipment and boilers, as well as a manufacturer of water treatment products for residential and light commercial applications. A. O. Smith is headquartered in Milwaukee, Wisconsin, with approximately 12,000 employees at operations in the United States, Canada, China, India, Mexico, the Netherlands, and the United Kingdom. Main Function