hi, i have a hot water based board heating system that the OLD thermostat only needs 2 wires (red and white) to operate. However, i do have a third unused wire that is available to use as part of the existing wiring system, the third wire is NOT currently connected to anything. My issue is that my Boiler only has 2 wires connections on the terminal and after searching and watching many help videos online, no one ever addressed the boiler system hookup. What should I do if there is no additional terminal on my Boiler to connect the third wire to use as the "C"ommon wire? I have bought 5 2020 Nest Thermostats for my house as I have 5 zones heating and the Nest thermostats are all disconnected from the Wifi system due to insufficient power.
I have thought maybe i can add the google power connector just to the unused wire by the boiler terminal and just provide the power then i can connect the wire to the nest thermostat but not sure if that will resolve the issue.
any suggestions/recommendation are welcome
thanks
