Smart Thermostat for Ancient Wall Furnace

[suckerformimi]

I have an old 2-wire furnace. How do I connect a smart thermostat to it? The furnace only supports 2 wires and takes no power. It has a pilot light and presumably a pilot generator. So I think I need a solution that gets the power from something other than the furnace.

Thanks for any help here. I have been searching all over.

 

[turtile]

 

[suckerformimi]

Thanks, but the boiler in the video supports a C wire. I am looking for a way to hook up to a wall furnace that only takes 2 wires.

 

[herm0016]

iThe ecobee comes with a transformer. you may want to give them a call just to make sure it will work though. I am not sure if there is a minimum control voltage that it would need to pass in the transistor? i have installed them on 2 wire systems, but not one powered just with a millivolt generator.

 

[Fanatical Meat]

As above ecobee seems to fit nearly everything and at least as of four years ago their support & sales support is first class.

 

[deadlyapp]

You should be able to hook up any newer thermostat, you'll just need a separate transformer that will provide your "C" wire since your furnace may not easily provide it (although likely does if you pull it open).

 

[herm0016]

sounds like its old school with a millivolt generator. no transformer or control voltage needed.

You should be able to hook up any newer thermostat, you'll just need a separate transformer that will provide your "C" wire since your furnace may not easily provide it (although likely does if you pull it open).

 

[Sukhoi]

Check how many wires are actually in the wall. If you're lucky they ran 4-wire instead of 2-wire. You might be able to use a transformer to provide the C wire at the furnace end and use a normal thermostat, which will look nicer than having to run a power cord from the thermostat.