How good are mercury thermostats?

Fizz

Getting impression that mercury t-stats are very good! The one I have when adjusted to proper heat anticipator setting is very accurate, and seems like it'll last forever, as it's already 40+ yrs.

Jamie Hall

They're superb. Along with mercury pressuretrols and vapourstats. The contacts (mercury) do last forever, there are very few moving parts, etc. etc. If you have one, keep it! Far superior to the newer ones, either all electronic (for thermostats) or microswitches (for pressure controls).

The only thing wrong with them is you don't want to smash the mercury bulb and drink the mercury. So who's going to do that?

ratio

Yup. Mercury stats & roaches are a few of the things that will survive Armageddon. Couple one with a millivolt gas valve on a 1 pipe steam system & you'll be about as well set as possible for the coming grid collapse.
But, you can't change the setpoint from your iPhone, so fail.
</humor>

Fizz

Hey, I used to play with Mercury when I was a kid, now 70, so I'm glad I didn't drink it. Like most other things that last forever or for what they were used were very good are now on forbidden list. Where have the roaches gone???

BobC

I have a mercury contactor I took out of an old wave solder machine. It's rated at 50A 240V, it has two capsules about 3" long that are about 1/3 full of mercury. When the coil energizes two slugs get pulled into the mercury pools.

It was over 40 years old when I removed it and worked just fine thank you.

Bob

Canucker

Very good?! You can have my mercury filled T87 when you pry it from my cold, dead hands

BobC

I have 2 T87's (low temp version) sitting on the shelf downstairs, I never throw anything out.

Bob