Thermostat Wiring Colors Code [HVAC Wire Color Details] Thermostat Wiring and Wire Color Chart – Thermostat Wiring Colors Code; Tstat Terminal Designation: Color of Wire and Termination: R – The R terminal is the power. This is a red wire and comes from the transformer usually located in the air handler for split systems but you may find the transformer in the condensing unit. Have a carrier thermostat that has 6 wires 6 colors that Mar 11, 2010have a carrier thermostat that.. have a carrier thermostat that has 6 wires 6 colors that correspond to the wiring diagram The hvac system has a heat pump. I was told by Honeywell to buy their th5220 The wiring seems to not correspond correctly The red green yellow and common are the same however the white and orange are different.Hello, the white wire needs to go on Aux and the orange to the reversing valve (O) Did you have an E hooked up on previous stat? and is O set..The O terminal wire is what decides cooling/heating. Is the menu set up for O terminal to be energized in cooling?2 heat/one cool with auxActually E and aux are usually jumped together. I would leave on auxThank you for our patience!