Goodbye to My Henry Drefuss-Designed Dumb Round Classic Honeywell T86

An old Honeywell thermostat mounted on a wood surface.

midnightcomm / Flickr / CC BY 2.0

It was a design classic, the Honeywell T-86 thermostat. Designed by Henry Dreyfuss and introduced in 1953, it's in the Smithsonian and the Cooper-Hewett exhibited it, and wrote:

Its low price and ability to fit most situations has made the Round one of Dreyfuss's most successful designs. His continuing emphasis on ease of use and maintenance, clarity in form and function, and concern for end-use helped make Honeywell a leader in the field of controls both domestic and industrial environments.

Courtesy of Lloyd Alter.

It might well have been on the wall of my house since 1953, and probably would have worked for the next 60 years; it is so simple. A bi-metal strip wound into a coil winds and unwinds according to temperature, causing a big vial of mercury to tilt up or down. When the blob of mercury rolls over and covers the two contacts, the circuit is closed. Clever and simple, intuitive and easy to use, and since I have big cast iron hot water radiators and no air conditioning, that's pretty much all I need.

side of thermostat

Courtesy of Lloyd Alter.

Except Ivan the heating contractor says that after such a long time the bimetal strip actually wears out and is no longer accurate, that he isn't happy having my brand new boiler connected to a sixty year old thermostat and he has this new electronic Honeywell in the truck that he wants to install instead. He promises that the old one will be properly recycled; he sends them to the Clean Air Foundation, which runs the Switch-Out program that recovers mercury from thermostats and light switches. And it has been one of the goals of my renovation to get all the mercury out of the house.

new thermostat

Courtesy of Lloyd Alter.

Out of the bowels of his truck comes a hideous piece of plastic with batteries and cooling controls I don't need and setback features that don't work well with old hot water systems and their thermal lag, or in a house with a rental apartment where the occupants keep very different hours. It butts up against the doorframe. It looks awful.

I'm surprised that a company which appears to value its design history and heritage can turn out such a thing. They write about the T-86 on their website, still sell a mercury-free version of it (which I am going to buy and give this one back to Ivan) and paid attention to the design of their new Lyric.

But it is also so typical of so much electronic stuff, offering more features than we need with greater complexity and more batteries than we want, with a build quality that most definitely will not last sixty years.