Another relic from days of old.........

KEV 1 N · Jan 21, 2019

Found this in an old boiler room.....
It looks like a thermostat, there’s an old 2core micc that’s been chopped off, and also two mini bore copper pipes that connected into the bottom. I’m guessing the mercury must rise with the temperature and activate the switch.....Lucien will no doubt know exactly how it works!

[ElectriciansForums.net] Another relic from days of old.........

Pete999 · Jan 21, 2019

Thermostat of some sort, or maybe a pressure stat, bimetallic spring operating a mercury switch, in those days at least you could see what was supposed to happen.

telectrix · Jan 21, 2019

do not throw that away. if lucien do'n
n;t want, i got a place in my lab 4 it.

snowhead · Jan 21, 2019

I'd say it's a diffential pressure switch, usually fitted across a pump to prove flow .

Deleted member 26818 · Jan 21, 2019

It’s a thermostat, used to switch higher amperage.

KEV 1 N · Jan 21, 2019

snowhead said:
I'd say it's a diffential pressure switch, usually fitted across a pump to prove flow .

That makes sense, the room i found it in has a calorifier tank, and the actual “boiler house” is at the lower level outside, there’s a flow and return entering from the location of this Bolier house, the stat was located where the pipes enter the calorifier room, the old mini bore pipes disappear down the old duct!

SparkyChick · Jan 21, 2019

A quick Google revealed this snippet...

"A further refinement, known as the variostat, is a device which causes heat requirements to be anticipated according to the vari-
ations in outside temperatures, and this enables a more constant
temperature to be maintained inside."

That's from a digitised copy of "The Building Services Engineer", around 1935.

Full text of "The Building services engineer" - https://archive.org/stream/buildingservice00unkngoog/buildingservice00unkngoog_djvu.txt

Pete999 · Jan 21, 2019

SparkyChick said:
A quick Google revealed this snippet...

"A further refinement, known as the variostat, is a device which causes heat requirements to be anticipated according to the vari-
ations in outside temperatures, and this enables a more constant
temperature to be maintained inside."

That's from a digitised copy of "The Building Services Engineer", around 1935.

Full text of "The Building services engineer" - https://archive.org/stream/buildingservice00unkngoog/buildingservice00unkngoog_djvu.txt