I currently have a Honeywell T841A1217 and want to install an RTH7600. The wiring labels are different. T841A1217 has W2,X,O,E,G,Y,R. The RTH7600 has C,G,Y,O/B,RC,R,AUX,E,L. The RTH7600 also has C,G,Y,W,RC,R,W2,Y2.
I have a 2.5 ton Carrier Heat Pump.