I have an oil fired furnace with 3 heating zones using the Taco zone valves. I had one Nest E thermostat without a C wire that is installed with good voltage. I tried to installed 2 more and started getting power error codes (voltage under 2.8). I purchased 2 power adapters (sounds like I'll need 1 more) however I'm not sure how to wire these up. I have two control boards it looks like. A Honeywell and a Taco control board. At first I assumed the Taco control board went to the taco zone controllers, but I think after tracing the wires, it only controls my hot water, is that possible? I read that I may need 24v adapter thing as well? Or is that likely already installed somewhere? I'm ready to just hire a pro for this, but just trying to get some thoughts first.
Just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.
I appreciate the help, Mel.