Replacing Trane XL600 thermostat with Nest Learning thermostat 3rd and 4th gen

[TheKid87]

I’m wanting to replace 2 Trane XL 600 thermostats with a 3rd gen and a 4th gen Nest learning thermostat. Isn’t compatible and if so, which wires go where? 

I’d post a pic of the current wiring but cannot see how to add it here. 

[Patrick_Caezza]

@TheKid87 

The Trane thermostat is compatible with either of the learning thermostats.

Post a picture of your current thermostat's wiring here.