Who invented the thermostat?

The thermostat was invented in 1885 by Albert Butz and was called a "damper flapper." This first thermostat was nothing more than a furnace flap, which lifted as the room cooled and lowered as the room warmed.

By the early 1900s, Butz's thermostat patent had been bought by Mark Honeywell. Honeywell later added a built-in clock to the original design, which allowed homeowners to turn down the heat during the evening and pre-set the temperature for the morning. Since the addition of a built-in clock, other improvements to the thermostat include digital screens, touch screen technology and wireless remote access.