Honeywell T8095 Chronotherm Thermostat

Honeywell, Inc. of Minneapolis, Minnesota manufactured this Honeywell Comfort T8095 Chronotherm thermostat around 1977. This front face of the thermostat features a clock, thermometer, and two (red and blue) temperature setting levers. For heating, the left (blue) lever sets the lower temperature when the clock hits a blue pin, and the right (red) lever sets the temperature for when the clock has a red pin. The red and blue program pins are inserted into the clock, switching the furnace on or off to heat the house to its setting. The thermostat operated via a bimetallic strip and mercury tube, — the bimetallic bar would move one way when the temperature dropped, and another when the temperature rose. This movement shifted the mercury in a tube, opening and closing a circuit inside the tube when the mercury flowed to one side or the other.
The ubiquity of thermostats in 21st century homes shrouds the decades of innovation, industrial design, and engineering that went into making them an everyday object in almost every home. In the early 20th century, a majority of American households still heated their homes with manually operated furnaces that required a trip down to the basement and stoking the coal fired furnace. Albert Butz’s “damper-flapper” system was patented in 1886 and allowed home owner to set the thermostat to a certain temperature which would open a damper to the furnace, increasing the fire and heating the house. Progressive innovations allowed for the thermostats to use gas lines, incorporate electricity, turn on at a set time, include heating and cooling in one mechanism, and even connect to the internet.
Currently not on view
date made
ca 1977
overall: 6 5/8 in x 4 in x 2 1/4 in; 16.8275 cm x 10.16 cm x 5.715 cm
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accession number
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Work and Industry: Mechanical and Civil Engineering
Domestic Furnishings
Engineering, Building, and Architecture
Data Source
National Museum of American History


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