12.10-4: Minneapolis Honeywell 1934 'Chronotherm' Room Thermostat

HHCC Accession No. 2006.092HHCC Classification Code: 12.10-4

The ‘Chronotherm’ room thermostat with ‘Telechron’, synchronous, electric motor driven automatic night set-back, helical bimetal temperature sensor, low voltage, snap action, open contact switching, and mercury glass stem thermometer, would prove to be iconic in its times, a precursor of much to come in layered, multi-functional, consumer technology for the Canadian home, Type T12, Minneapolis-Honeywell Regulator Co, Minneapolis, Minn., Circa 1934

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12.10 Pressure Atomizing Oil Burner Equipment and Systems - Room Temperature Thermostats


Minneapolis Honeywell


Minneapolis Honeywell Regulator Co., Minneapolis


Type T12, See Note

Serial No.:

3 x 3 x 8’h


2 lbs.




Exhibit, education, and research quality, illustrating the engineering design of automatic oil heating, thermostatic controls with synchronous motor driven night set back feature, in the early years of the 20th century

Patent Date/Number:

From York County (York Region) Ontario, once a rich agricultural hinterlands, attracting early settlement in the last years of the 18th century. Located on the north slopes of the Oak Ridges Moraine, within 20 miles of Toronto, the County would also attract early ex-urban development, to be come a wealthy market place for the emerging household and consumer technologies of the early and mid 20th century.

This artifact was discovered in the 1950’s in the used stock of T. H. Oliver, Refrigeration and Electric Sales and Service, Aurora, Ontario, an early worker in the field of agricultural, industrial and consumer technology.

This particular specimen was installed in a home in York County [York Region] north of Toronto, in the late 1930’s, where it operated satisfactorily into the mid 1980’s.

Type and Design:

Helical by-metal spring actuated, ‘Telechron’, synchronous, electric motor driven automatic night set-back low voltage, snap action open contact switching, mercury glass stem thermometer,

Special Features:
Performance Characteristics:
Control and Regulation:
Targeted Market Segment:
Consumer Acceptance:
Market Price:
Technological Significance:

The T12 makes use of Series 10, three-wire thermostat circuitry with heat anticipator, bringing the heating system on sooner than otherwise, in order to reduce the thermal lag in the heating system.
The introduction of the automatic, time/temperature actuated control systems for home heating was as much a marker of profound technologic change as it was socio-cultural change [see below]. They introduced layered, multi-functional, consumer technology to the Canadian home [devices that would perform more than one function]. Such devices were iconic in their impact and consequences for Canadians, beginning to suggest the power of technology and its potential for shaping and constantly re-shaping the life of Canadians throughout the balance of the 20th century.
With the introduction of automatic night set-back thermostats in the late 1920’s through early 30’s, by both Time-O-Stat and Honeywell, the automation of the Canadian household was ratchet up one more notch, It would seem, at the time, that the automation of home heating comfort, by the HVACR industry, had gone as far as it was likely to go. Such, however was not the case, however, with a myriad of new consumer devices to follow, with for example automatic: heat anticipation [See ID 220], humidity control [See ID 222], air filtration [See series 15.06, early air filtration technology, area temperature zone control and integrated heating/cooling controllers [See ID 217].

Industrial Significance:

Earlier versions of the technology, using an 8-day wind-up clock, are shown in Time-O-Stat’s product catalogue with patent numbers sited back to 1928. The development of the miniature, self starting, synchronous, alternating current motor technology by Telechron, and the mass production of motors for electric clocks and timing devices, was in itself an significant scientific, engineering and manufacturing accomplishment for the period - with applications and benefits which would be far reaching.
Following the introduction of small synchronous type motors for electric clocks in the early 1930’s Minneapolis-Honeywell introduced their “Chronotherm”, a basic technology that would appear in various forms through to the introduction of digital control technology in the 1990’s.

Socio-economic Significance:
Socio-cultural Significance:

The automatic night setback thermostat found a market even in the late 1920’s for setting the night-time temperature of the home back to a predetermined time and temperature, in order to save fuel and provide a cooler house for sleeping. The promotion not-with-standing, one might guess that the public appeal [to all that could afford this technology] was much more that of personal pride and prestige of ownership, keeping up with the latest and the best, than with cost savings. These devices, costly and constantly requiring service, would be seen as eat up fuel savings. This situation would change significantly, however, towards the end of the century, with shortages and erratic markets in the petroleum sector Energy suppliers and government agencies would be seen encouraging the use of such devices, by then considerably more sophisticated and reliable, employing electronic digital technology.
Such temperature and time actuated, automated devices marketed with great success for the Canadian home in the early 1930’s would change forever the expectations of Canadians for winter comfort and convenience. An industry promotion in the National Geographic in 1928 promised the householder “June comfort on every zero morning”. The marketing of automatic oil heating had become part of the main stream of the new consumerism in North America, now the subject of national advertising campaigns.
But it was still the early 1930’s and technology in the home was as yet not a common experience. There was, in fact, still much public concern about the presence of electricity in the home, and electrical appliances of any type, especially heating ones which would operate automatically, coming on and off without the touch of human hands. They were a source of suspicion, often fear and mistrust, while at the same time being objects of intrigue, especially for the well-off who could afford to be intrigued. But it was a period, too, were there was a new desire for the comforts of home all that could be afforded in a period of wide spread economic depression.
Manufacturers of the new technologies for the home would take full advantage of the public mood, as a consequence 20th century marketing was born and along with it the use of often shameless hyperbola on a level not here-to-for found in the market place For many Canadians the words ‘oil heat’ and ‘automatic’ highly promoted, where to become synonymous with a new lifestyle, comfort and convenience, and a new popular wisdom of what 20th century life was all about, Such words would herald the promise of a new future for those that could afford it. Such terms would be part of an advance guard that would quickly follow with the advance of ever more intrusive mechanical, electric, electronic and digital technologies. These technologies would serve to reshape every aspect of human and community life. They would be the building blocks, part of a new, manufactured 20th century reality, bringing with them new encoded information, ideas, myths, beliefs, traditions expectations and wisdom’s that would multiply and dominate North American life through into the 21st century. The study of culturally induced meanings and cultural significance inherent in the vast array of three dimensional objects, with which Canadians would increasingly surround themselves, starting in the early years of the 20th century, would become the subject of scholarly study well before the end of the century. For Canadians, the interest would be in coming to recognize and comprehend the messages encoded in Canada’s rich material culture, learning to read what has been called the new cultural ‘hieroglyphics’, understanding their meanings and significance for our times. The educational outcomes would be tied to helping peoples to make sense out of the overcrowded conceptual field of encoded information, ideas, myths, beliefs, assumptions, traditions expectations and wisdom’s that crowd in on them from every hand in the culturally complex societies which now exist largely throughout the Western world .


G. Leslie Oliver, The T. H. Oliver HVACR Collection

HHCC Storage Location:
Bibliographic References:

Automatic Controls and Recording Instruments. Minneapolis-Honneywell, allied with The Brown Instrument Co. Cat. No 1, Feb. 1935 This night set back thermostat by the Minneapolis- Honeywell Regulator Co., is illustrated in a November 22, 1932, product sheet, bound in their Reference Manual for the “Installer and Service Man”. Reference manual for Installer and service Man, Minneapolis Regulator Company, 1932-33 Also See foot notes


Telechron motor is Type B6, Model 420M39, Warren Telechron Co. Ashland, Mass

  • CMX02; CMXo4, Item H20

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