Originally Posted by oleegarza
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?