I have a Taco SR506 relay running 5 zones of heated floors. 3 of the zones I'm running with manual thermostats. 2 (zones 3&4) I'd like to run the Nest Learning thermostats. I was told by Taco I should be able to run 2 Nest Learning Stats without running into power issues and these are the only two zones I'd like to run a smart stat on. I was trying to hook up 2 Google Power Connectors to zones 3 and 4 yesterday and was going to put the C wires into the Com hookup under the 24 VAC spot on the left of the picture.
However, I noticed a resistor and a white wire running to the W slot in Zone 5 and stopped because I didn't understand what our installer was doing there. We don't have a zone 5 in use.
Three questions: 1. Should I go ahead and wire the C wire from the two Google Power Connectors for zone 3 and 4 to the COM port and just leave the resistor and white wire running to W in Zone 5? 2. What do I do if the C wires from the 2 Google Power Connectors won't fit into the COM port? 3. Is that white wire sending COM power to the W in Zone 5 and is that where I could send the C wires for the Google Power Connectors? I guess I really don't know why that wire is there!
(note: Zone 4 thermostat wires are missing because I had already removed them in anticipation of adding the Google Power Connector there before I stopped to take the picture.)
