Hi - I have added an outdoor wood furnace to my heating system (hot water boiler) and I need to add a zone valve to control the flow of hot water. I have a Taco 572 3 wire zone valve along with their wiring diagram, but it isn't clear how to wire it into my existing system. See my diagram below of my existing system. Can someone explain how to wire this in? Do I need to have a seperate transfomer for this zone valve? What is #3 terminal for? It seems terminal #1 & #2 would do the job.