Nest thermostat gen 4 wiring with ventilator and humidifier

[jaytang]

Just want to confirm the compatibility before I make the purchase. Currently the entire system (conventional AC/heat, ventilator, humidifier) is controlled by Honeywell Prestige IAQ. So it has an EIM which has most of the wiring and the thermostat only has R and C. Ventilator and humidifer are using U1 and U2. How do I wire the system, if possible, with nest thermostat gen 4? I can't find a wiring diagram for the new thermostat. Is it available somewhere?

[ovidioj]

Hello @jaytang,

Thank you for posting in the community. 
I appreciate the detailed information you posted. Let me tell you that the Nest Thermostat Gen 4 is generally compatible with most 24V HVAC systems, including gas, electric, oil, forced air, heat pumps, and radiant, and the specific wiring configuration will depend on your HVAC system's setup. I recommend consulting with a qualified HVAC technician for optimal performance and to ensure correct installation. They can assess your system and provide tailored guidance.

I hope this information helps. If you have further questions or require assistance, please don't hesitate to reach out.

Regards, 
Jorge