I am trying to setup a Nest Thermostat and I am getting a few errors when trying to set it up. I am getting errors that no wires are detected on the Nest even though the old thermostat is detecting the wires and working fine. I read online that I need to add a C-Wire. My current thermostat needs 4 wires (G-R-Y-W).
When looking at the zone control board, I only see those 4 terminals and no C-wire terminal. Do I connect the C wire to the com D+ port?
I have a ZTECH ZCV2 2 Zone HVAC Control Unit.
I would like to replace the two thermostats with two Nests. Meaning I would like to connect two Nests to the zone control unit.