Is a learning nest 4th gen thermostat compatible with my system?

[remhat]

My system is using 3 wires: D,R,B

Yellow wire goes to D

Red wire goes to R

White wire goes to B

[GBD]

with D,R,B connections you're probably looking at some version of a Trane comfort link system. If so the Nest thermostat wouldn't be compatible and you'll need to look into a Trane comfort link smart thermostat if connectivity is what you're after.

[remhat]

Thank you.