I have a Trane heat pump, model # TWV025B140A1. And a Hunter 44760 thermostat I want to install as I my other one is going bad. Here is the wiring diagram coming off my old thermostat.
G green
Y yellow
E black
O orange
X1 blue
W2 white
R red
And there is a brown wire not connected to anything.

Wiring diagram off the new thermostat
R 24V ac supply
Y1 Compressor stage 1
W2 Aux heat
E Emergency heat
O Reversing valve cooling mode
B Reversing valve heating mode
G Fan
L System monitor
C 24v ac common

The first thing that jumps out at me on the cross reference chart that came with the thermostat says that on a trane heat pump that B is the 24 v common, there isn't a wire hooked up to B on the old thermostat. What can be done about that?

And last if the 24v common wire problem can be fixed, would it be hooked up like this on the new thermostat

R-Red
Y-Y1
W2-White
E-Blue
O-Orange
G-Green
And where does the black wire go that was connected to E?

The cross reference chart can be found at this website on page 7.

http://www.hunterfanhq.com/tools/sales/hunter/preseason/images/owners/44760.pdf

Thanks in advance for any advice,
Chris

 

I believe your X1 terminal on the old thermostat is the 24volt common. The blue wire will connect to the new C terminal. So almost everything else should fall into place. You will not connect anything to the B terminal of the new thermostat or the L terminal. Is there a note about adding a jumper from E to W2 on the new thermostat? Usually there is a note showing howto do that.

Ken