I have a Trane XE 1200 Heat Pump and am trying to install a programmable Honeywell RTH7500 thermostat and have an extra wire. The previous thermostat was a manual Trane. I connected the Blue wire to the C terminal, the Yellow wire to the Y terminal, the Green wire to the G terminal, the Orange wire to the O/B terminal, the Red wire to the R terminal which has a jumper to the RC terminal, the White wire to the Aux terminal, and the X2 wire to the E terminal. I still have a brown wire that was connected to the T terminal that is unattached. Last night I set the temp to 76 degrees and the room temp never got over 71 and the AUX HEAT was displayed all night. Does that T wire need to be connected anywhere and is my heat pump and/or Aux heat shot?

I have a Trane XE 1200 Heat Pump and am trying to install a programmable Honeywell RTH7500 thermostat and have an extra wire. The previous thermostat was a manual Trane. I connected the Blue wire to the C terminal, the Yellow wire to the Y terminal, the Green wire to the G terminal, the Orange wire to the O/B terminal, the Red wire to the R terminal which has a jumper to the RC terminal, the White wire to the Aux terminal, and the X2 wire to the E terminal. I still have a brown wire that was connected to the T terminal that is unattached. Last night I set the temp to 76 degrees and the room temp never got over 71 and the AUX HEAT was displayed all night. Does that T wire need to be connected anywhere and is my heat pump and/or Aux heat shot?

You might want to look at the legend below.
NOTE You have a trane heat pump and see in the legend where the brown wire is used.
You might also check the sticky notes at the beginning of this board to see other wiring ideas.
If you marked the old wiring as you removed it from the old thermostat it is usually very easy to change the wiring over to the new thermostat.
Also read very carefully pages 10,11,12 in your manual. There are very specific changes you have to make depending upon how the old thermostat was wired. I have included a on line link for your thermostat. That is also below. Good luck.

http://customer.honeywell.com/techlit/pdf/PackedLit/69-2104ES.pdf

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