I have a 4 zone valve boiler system. Each of the zone valves is Honeywell. I have a 24-volt transformer along with an aquastat.
I have attached a photo of the wiring diagram from what I can tell looks like.
The technician I had to our home was able to hook up an ecobee to the family room zone using a pek on the central air handler. He installed one on the upstairs 2nd floor zone valve by attaching a extra green wire that was unused in the bundle and switching some of the other wires around. After completion he said that the original installer had some of the wires backwards for the 2nd floor zone valve. I looked at the results and there are only 3 wires going to the thermostat r, w, and c.
I was hoping to hook up the other 2 zones (basement and living room) myself based on how he installed it, but im not having luck. when the green is attached in the basement, the ecobee continues to start and reboot. When the green is attached in the living room zone, the ecobee appears to work but eventually reboots ( I think this may have only let me go through setup when the heat was on in another zone).
I tried calling Ecobee support but they only said I should use a separate plug in transformer because I may be trying to draw too much current