I have a geothermal hvac system, with a humidifier. My current thermostat has 3 wires connected to thermostat. Red, White, Blue. Other wires are in wall. How do I wire NEST thermostat?
Thanks for reaching out. I'd like to check it further. Could you please provide a photo of the wires connected to your thermostat and to your HVAC system control board? Ensure that the labels of the wires are visible. What is the make and model of your HVAC system? Also, in what country are you located?
