Founded in 1923, A. Treffeisen & Son is a plumbing, heating and electrical contracting company. It provides a range of services that includes installation, repair and replacement. It offers various types of products, including boilers, heaters, and ventilation, electrical and temperature-controlled systems. It serves a variety of customers, such as hospitals, hotels, homeowners, retail outlets, municipal facilities, educational and financial institutions, and manufacturing and industrial companies. Its clients include Kraft Foods, Corning Glass, Fox Hospital, Amphenol Aerospace, Mallinckrodt and Tyco International and the National Baseball Hall of Fame. Headquartered in Oneonta, N.Y., A. Treffeisen & Son is a member of the Associated Builders and Contractors.