Trane heat pump compatibility

[CaptainChaos69]

Bought the lower (non-learning) Nest to use with Trane XR. I read that this unit will work with Trane and it won't. Already took the old thermostat off. Can I use this Nest or not?

https://photos.app.goo.gl/rKPGNAk1eJ3aCq1b9

[Patrick_Caezza]

@CaptainChaos69 

It should be compatible and it looks like you have a Heat Pump so you would use the lower terminal labels.

You will also need to look in the furnace/air handler to see why there is a white and black wire on the W2 terminal.

[CaptainChaos69]

Thank you so much for replying. The air handler is literally encased in the wall so I don't have access without removing part of the wall. I just bought this place, no idea why it's like that. Think I'll have to call a tech, have it serviced and pick their brain. Thanks