Our Founder

Warren Johnson, founder of Johnson Controls

Warren Johnson

Born in 1847 to pioneer Vermont farmers, Warren Seymour Johnson grew up in poverty on a homestead in western Wisconsin. Life was hard. Johnson had to make his own clothes out of canvas and dye them with ink for color.

Living with scarcity did nothing to diminish his burning desire to learn, however. Self-taught, with little formal schooling, he had a gift for discovery. Even as a young boy, he kept a book in which he sketched and described mechanical, chemical and electrical inventions. Despite his lack of education, he became a surveyor, a country school teacher, a superintendent of schools and, from 1876 to 1883, a professor at the State Normal School in Whitewater, Wisconsin.

Colleagues there considered Johnson “one of the most strikingly original teachers.” He taught mathematics, science, drawing and penmanship, but his real passion remained experimentation and invention. In his private laboratory he conducted experiments in many areas, including electro chemistry—a glamour science of the day.

Winters in Wisconsin can be harsh and, unsurprisingly, Professor Johnson’s classroom was either always too cold or too hot. It was uncomfortable, and it meant constant interruptions by a janitor who came in to check temperatures and then adjust the basement furnace dampers. Johnson set out to solve the problem.

He toiled for three years to invent a device that could control and regulate room temperature and, in 1883, he received his first U.S. patent for the “electric tele-thermoscope.” The mechanism, which would become known as the electric room thermostat, used a sealed bimetal element with one wire of an electrical circuit attached to the fixed end, and the other wire connected to a small pool of mercury in a cup-like reservoir. Changes in air temperature moved the free end of the thermal element into and out of the mercury to close or open the electrical circuit, which in turn controlled his classroom damper in the basement. It was an invention that would launch an industry.

The electric tele-thermoscope patent document
Photo of Johnson Controls founder, Warren Johnson with the sales staff

Johnson moved to Milwaukee—Wisconsin’s largest city—to develop his ideas. Two years later, his wife Cora and two sons joined the inventor, who had by then formed a partnership with local businessman and financier William Plankinton. In 1885, the same year Mark Twain published Huckleberry Finn and Johannes Brahms wrote his final symphony, Professor Johnson and William Plankinton launched The Johnson Electric Service Company.

Considered an “intelligent, egotistical, artistic and demanding leader,” Johnson ran the company for 26 years. His passion for invention continued throughout his life, resulting in 50 patents. He died of kidney failure in 1911 while on a trip promoting a custom automobile business that had become part of his namesake company.