oilman wrote:Stay away from any "power stealing " thermostat- this would be a digital style that does not have 2 to 4 aaa or aa batteries. They don't work right and they can also damage oil and gas controls on conventional heating units.
I am of just the opposite opinion. I would never have a thermostat that forced me to spend $4 every year or so. I purposely look for thermostats that do not need batteries replaced and that are powered by the same 24 volts AC that powers the boiler controls. I have never known one to damage controls, nor do I understand how one could, nor how you would know or prove that a thermostat caused damage to controls.
A thermostat should last about forever, but, for sure, this transition to non mercury thermostats has not been good. There's a bunch of junk out there and most manufacturers have had growing pains and a learning curve that is taking them off the road. Basically, stick with a name brand and try to pay more than $10 for a one.