Minneapolis-Honeywell T852 Electric Clock Thermostat

The Minneapolis-Honeywell Regulator Company manufactured this Honeywell T852 electric clock thermostat beginning in 1960. The thermostat had two external tabs for setting the temperature for daytime and nighttime. The thermostat connected to the house’s electric system so that it did not have to be wound or set.
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
overall: 4 3/4 in x 2 3/4 in x 2 5/8 in; 12.065 cm x 6.985 cm x 6.6675 cm
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Work and Industry: Mechanical and Civil Engineering
Domestic Furnishings
Engineering, Building, and Architecture
Data Source
National Museum of American History


I recently purchased a home built in 1905 that has this same model thermostat running the oil / steam radiator heating system. It seems to work well, but I am about to attempt replacing it with a modern programmable thermostat. I have a feeling the wiring may be a challenge as the new thermostat uses low voltage only.
Recently purchased a house and yes this same model is on the wall and it still works.

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