I have purchase a Honeywell programmable thermostat for my Trane heat pump with auxillary/emergency heat and when I look at the current wiring to the Weathertron BAYSTAT240 it goes like this:
Terminal:Wire Color
R:red
T:brown
O:orange
Y:yellow
X2:Blue
B:Black
W:White
F:Nothing attached
U:Looks like a tiny jump/bridge to W

My confusion lies with the black and blue for the new unit. Most other forums show the same above but with the black and blue reversed:
B:Blue
X2:Black

My new thermostat a Honeywell 6320U lists the following terminals to be used for the setup on a 1 Cool/2 Heat, Heat pump with auxillary/emergency heat:
RcR
Y
C
O/B
G
Aux/E
L
What color wires should be attached to each of the above? I mostly don't understand what to connect to C, Aux/E and L. I'm wondering to if there was a mistake made all the way out to the outside unit in using black rather than blue for the B terminal on the original Weathertron. I plan to look at the heat pump in the morning to see if the colors are reversed there also.

Thanks a bunch in advance.

Thanks

You might look at these under GE Bay
You will not be using the T terminal I believe
You will have to select B or O in the program I believe

After some debate and viewing some other questions/answers on this site, I determined when switching from my Weathertron BAYSTAT240 to the new Honeywell TH6320 programmable thermostat that I would connect as follows:

Terminal:Wire Color
Rc&R(bridged): Red
Y: Yellow
C: Blue
O/B: Orange
G: Green
Aux/E: White
L: None, but perhaps I'll find out there is a problem when using them. Heat in the winter since the Honeywell installation guide says this "Sends output when set to Em. Heat".
I left the brown and black wires unattached to anything but taped and secured for later use if necessary.

I flipped the breakers on the air and everything worked fine. As a side note I had another thermostat upstairs that was much easier to change over since it was digital and had very similar designations to the new programmable units I had ordered from BuyPlumbing.net. Knowing this thermostat controlled a very similar unit to the one for the downstairs heatpump and airhandler made me feel confident about connecting the blue wire and not the black to the "C" terminal on the new thermostat. I installed the Honeywell 6320 for both the upstairs and downstairs and hope I love the programs rather than hollering at the kids to readjust their thermostat.

Thanks