Compatible with gen 4 nest learning thermostat?

[Elizabethcroc]

Our current set up is above. If our wiring is compatible with the gen 4 learning thermostat can somebody please tell me what color wire needs to hook up where? The black wire is the one I’m most confused about, everything else seems pretty self explanatory but if somebody with significantly more knowledge could break it down into easy steps I’d be so grateful! 

[Patrick_Caezza]

@Elizabethcroc 

It looks like your system is manufactured by Trane.

Give this wiring a try.

Blue - B to C

Red - R to Rc

White - W to W2/AUX (set as AUX heat)

Yellow - Y1 to Y1

Brown - Y2 to Y2

Black - X2 to * (set as emergency heat)

Orange - O to OB

Green - G to G

[Elizabethcroc]

Thank you!!

anything specific I need to look out for to ensure it’s functioning properly or to know that it’s not? Our unit is pretty old so messing with it at all is a little nerve wracking haha 

[Patrick_Caezza]

@Elizabethcroc 

You'll know if it's not working correctly.

Just follow the test steps in the setup.