Hi, my HVAC pro is unfamiliar with the Nest 2, and he is busy installing Honeywell HE300 humidifiers in my new HVAC systems.
Here is the HE300 wiring docs:
Here is the Nest humidifier docs:
From the Nest docs one option is to use a relay control:
But I think there is an easier way that does not require a relay; bridge the HUM terminals on the HE300, and to connect the * wire on the Nest to the W terminal on the HE300.
Bridge HUM: always call for humidity (replace humidistat).
* to W: Let Nest control when humidifier is on or off.
Am I on the right track?