This may be more of a generic electrical question but maybe someone knows. Here is my heating and cooling scenario. I have 2 thermostats for my boiler, its baseboard heat. Its a 2 zone system… 1 for the lower half of the house and the other for the bedrooms. I believe it’s a simple 2 wire setup at each thermostat, red and white wires are all I see. Can I plug in a simple 24v converter and run 2 c wires from 1 plug? Lastly, I believe my AC also does not have a C-wire. Can I run a 3rd wire to AC thermostat too?
For the lockstate adaptor which comes with two wires attached to it, one goes to the common on your thermostat and the second wire will go to Rh (so two wires on Rh. One is the regular red one existing wire from your two wire configuration and second one from the adaptor).
I am a complete noob as far as electricity is concerned. At least this model wouldn’t work for multiple thermostats is my guess. @Navat604 is the resident electrician and an expert on wiring.
I have the same heating setup as you and use 2 CT100’s. Luckily had common available for AC and using Ecobee3 for that.
Good advice Ron. I was thinking to use ct100s also because they don’t need a C-wire but I saw that new comparable 60 dollar Fidure thermostat and it looked damn cool so I wanted to look into it. Also, thinking ahead, it would be nice to have a C wire if I ever upgrade. AC is new, but boiler is pretty old. Anyhow, did you use the CT100 WITHOUT C-wires without any issues? Not sure how much more each does…set it and forget it basically. I do realize Ecobee and others have sensors you can use but I dont think Id find that too useful.
I used the entire last winter season without any issue without running the Common. I bought the adapters but too lazy to connect it and I know it will not meet the WAF as I can’t hide the wires. 
the battery held up good and I just changed it as heating season has started here in NE. The battery was still at 50%. Running a common gives you an added benefit of turning it into a zwave repeater. Zwave mesh is not an issue in my house. Keep in mind that CT100’s are dumb and scheduling/programming is done by some controller.
The only issue was me me messing up the device code. 
As such hearing is Weil McLain/AC Smith (gas) baseboard heating.
So programming is done at the unit, but you can do manual adjustments via ST? Seems REAL dumb, jk ;-). I keep thinking it may not be that hard to drop a C-wire at eact location. Bedroom is close to a plug in the attic. AC handler has power and its newer so there probably a way to add a C-wire there. The main living room area though is the one I have to figure out. Or again like you keep it simple and use the ct100.
You can definitely run a 24vac transformer and use it to power multiple thermostats. One thing to remember is how much power is needed and what’s the power output of your transformer.
If you are going this route. I would suggest running a cat 5 cable and replace the old wires as well.
It uses the regular thermostat wires! If I made any sense.
The main thermostat allows you to set your set points for heating/cooling etc. and works fine. But your daily, weekly and other programmable functions cannot be done on the unit. You need ST or some other controller to handle this. It’s dumb.
I say run that C so you can have more choices 
Wish you were in Jersey, my friend
1 Like