We purchased our home and it had the Nest Learning Thermostat installed and according to the information here it is the 3.4 version or Gen3. When I try to set up the Nest App but apparently the previous owner had it set up and so it says it is connected althought it is not connected by me so I cannot get access to information that is further into the process of how to resolve this issue myself. The wires are connected as indicated in the diagram. Please help. I have two disabled people living in the house and I need to get this resolved.
Why don't you just reset the thermostat to factory settings? Press the front of the thermostat, select settings and rotate the dial to reset. Then go through the menues to set it up again and fire up the nest app on your phone to add it to your google home.