Unfortunately the control board on our ERV has been fried since last summer. It was probably due to several experiments trying to get the Lutron Grafix 0 to 10 voltage dimmer to work with the ERV. My son bought a new board for me over a year ago but he also had a busy year. (Moving here!) He just got around to installing it last month.
The ERV worked again with the new board but I lost the original controller for the system. (I packed it away someplace safe!) He had to hook up the humidistat in the bathroom to turn on the unit. It is connected to the boost control so that runs the ERV at full power.
But my son is also interested in setting up the NEST thermostat control. After quite a bit of testing he found that both Nests I had tried to use to control the ERV fan had broken electronics to the G or the fan connection. They still work fine for the call for heat. So he connected one of the inner rings from a Nest that has not been broken. But that is not the only step in getting the Nest to work with the ERV. He is going to add a relay to the system. That will allow the ERV to be turned on from the living room Nest thermostat fan control. Using IFTTT the Foobot air quality monitor could turn on the Nest fan when air quality is low.
Next perhaps he will tackle the 0-10 volt system to see if that can control the ERV too. Nice to have someone more knowledgeable than I am to figure out and fix the problems I created.