I have a Lennox wall mounted boiler (gwm 075ie), I am trying to connect a "c" wire so I can install nest thermostats. I have 3 zones, currently running 2 wires (r&w). There is an extra wire behind each thermostat, that runs down close to the boiler, none of those wires are connected to anything. My current transformer is rated at 40va.
Unsure of the best way to do this. I have taco valves (z075c2-1) each valve has a "c" connector. Could I just run a wire to each of those connectors to the thermostat? Is the transformer able to handle 3 zones and 3 smart thermostats? Taco says a 40va transformer can run 12 valves.