I installed 2x of these in my condo a few years ago. It was built in the late 2000s, so an easy installation with all the right wires, etc. No issues. Works great.
Now I'm trying to install 3x of these in an older house (late 1960s):
* Boiler and radiator heat only (no AC)
* 3 zones
* 3 wire setup (R, W, Y)
* No C-wire, and not easy to run new wires
I've been through Youtube videos, chat boards, and even spent 2 hours talking to Ecobee on the phone today. I basically learned that I need a C-wire (already knew this), but I had expected that the third wire (Y) could be reconfigured to serve as the C-wire.
Because it's a 3-zone valve setup for the boiler, it's a huge jumble of spliced wires on top of the boiler. Maybe 15 years old, but still, a jumble. The people at Ecobee told me it can't be done. The people who installed the boiler said that's nonsense, it can totally be done, just needs to have the C-wire. But they couldn't run a C-wire for me.
Anyway, is this something that anyone here knows much about? Or has gone through themselves? I'm trying to avoid paying $$$ to have someone come out and install it, because except for the power wire, it's a very simple task to install it, that I can certainly do myself. That said, if a power wire is going to be necessary, yes, someone else can do that part for me.
