On 4/6/2018 9:10 PM, J.Albert wrote:
What I have:
Burnham gas furnace, hot water,
So....
I know there are "smart thermostats" one can buy, but I still don't know
if they can do what I want. Which is:
- set a high temp limit (furnace shuts off)
- set a low temp limit (furnace turns on)
Say, set my low for 64 degrees and my high for 70 degrees. Or something
like that.

Yes, but you don't have a furnace, you have a boiler. The boiler will
have limit switches on it that will shut it off at a maximum water
temperature for safety. The thermostat controls the circulator pump.