Seven decades later THERMOSWITCH® is still a solution for many applications.

Founders T.L. Fenn & Dr. Walters combined the letters from their last names to name the company.

Fenwal's original plant, located in the heart of Boston's science-industry community.

In April 2005, Fenwal Controls was acquired by UTC and is now a part of the Fire & Security Division.

1920s:

In the mid 1920s, a service engineer, Wilfred Turenne, developed and subsequently patented an accurate and reliable device that would greatly reduce temperature control problems in electrical appliances. The device, trade named THERMOSWITCH® (link to product information), later came to the attention of Dr. Carl Walter, who envisioned additional applications for this new control. Dr. Walter encouraged a local financier, T. L. Fenn, to invest in a new manufacturing company and further develop the THERMOSWITCH® product.

1930s-1950s:

The company's operations began in a small shop in Danvers, MA, and THERMOSWITCH® quickly established itself as a significant industry innovation. In 1938, Henry Warren, the inventor of the Telechron Clock, became a principal, and the company moved to Ashland, MA. In 1956, the company purchased a new plant in Framingham, MA, doubling Fenwal’s total floor space.

1960s-1970s:

The 1960's marked another significant technological development when Fenwal pioneered automatic gas ignition. The need for additional space to house this growing company led to the decision to build a new plant in Ashland. Due to rapid growth, Fenwal expanded the facility in 1965 and eventually consolidated all company operations into it. In 1966, Fenwal was acquired by Walter Kidde & Co., Inc., a well-known conglomerate. In 1971, Fenwal, along with several other subsidiaries, became a division of Kidde, Inc., a firm dedicated to fire protection, gas ignition and temperature control.

Present:

In April 2005, United Technologies Corporation (UTC) acquired Kidde, Inc. UTC continues Fenwal Controls’ technological innovation. Achieving Competitive Excellence (ACE), UTC’s proprietary technique now in use by Fenwal, is a process that will ensure best-in-class in products and processes.

Fenwal Controls today continues to enhance the manufacturing and application engineering that is housed within the Ashland headquarters. Visitors are encouraged to make an appointment to view our manufacturing processes, product breadth and Applications Lab services, and find out how Fenwal can help sharpen their competitive edge.