I have a Weatherman Model 38YKC carrier Heat Pump. Can anyone tell me if it is a single or two transformer system. The answer will determine the wiring of a Honeywell VisionPro 8000 Thermostat.

Thank you.

Usually if you have an electric furnace inside the transformer will be located in that unit and you will have one transformer but the actual existing thermostat wires will tell that also. I am sure you labeled the wires before you removed them as it says to do in the instructions. If not you will have to track/trace them down.

Thanks for your help. I did Label the wires and now need to install the new Honeywell VisionPro 8000 Thermostat. I have A Carrier Heat Pump (Model 38KYC) with the usual back-up/emergency electric heat strips (two sets of them). I have no outside sensors. Following is the wiring of the existing Carrier, Programmable Thermostat.

[24V] [R] [Red]
[Common] [C] [Blue]
[Fan] [G] [Green]
[Heat & Cool Stg. 1] [Y/Y2/] [Yellow]
[Heat Stg. 2] [W/W1] [White]
[Reverseing valve] [O/W2] [Orange]

Following is how I think the Honeywell unit should be wired:

[Heating Power] [R] [Red]
[Common from Secondary Cool] [C] [Blue]
[2nd. Stage Compressor] [Y/Y2] [Yellow]
[Auxillary heat Relay] [Aux] [White]
[Fan Relay] [G] [Green][Changeover Valve] [O/OB] [Orange]

Note: Terminals Rc, Y, E, L, S1, & S2 Not Used.

Note: I am not sure about the Yellow wire as to whether it connects to y or Y/Y2.

1) Do you agree with above wiring connections?

2) Do wiring changes need to be made to the air handler?

Thanks again!!