Can anyone help with figuring out wiring for the Thermostat? O/B vs O and B separate

Home
1

I currently have a Trane thermostat that goes with the Trane AC unit and Trane XR heat pump. Having trouble with the set up and understanding what i need to tell the app i have. It says i have a compatible system, but i’m learning that my wiring may be a little weird just because it’s a Trane system. Main issue is figuring out the heat pump and what to tell the app i have since it’s looking for O/B and i have them separate O and then B (see picture)
I’ve seen some say the B wire is like a C wire, but still very unclear.

IMG_1243
IMG_12431920×2560 190 KB

Top: Y2 W2 G W Y (R and Rc) so RC according to app
Bottom: X2 W1 G O B Y (R and Rc) so assuming Rc

I think i just need to figure out what to tell it because it’s not letting me move forward with the “preparation” stage.

When i put what i have It says it’s incompatible…

I’ve seen others have some success but unsure with my specific situation.

Thanks for your help in advance!

2

Is it possible to also take a picture of your HVAC system with the wires on it and where they connect?

1 Like
3

Yes, B is (C) common on a Trane system, You can tell it’s not a normal B wire because it is present on both sides of the thermostat label( heatpump and conventional heat/cool), and a conventional system would have no use for a changeover valve.

1 Like
4

Great info on the “B” wire. Will add tat to my info library. :slight_smile: