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cujosocal

Termostat wiring (4 wires with orange??)

cujosocal
12 years ago

After researching, it seems the normal color coding for a 4 wire system is R,G,Y,W... I don't have a white wire, appears to be orange instead! I have a Hunter 44110 that is replacing an old thermostat. The new unit had the folowing terminals: Rc/Rh (jumpered), G, Y, W,... So i hooked the wires up accordingly and hooking the orange to W (assuming they used orange wire instead of white)... turned the unit on and adjusted the temp on the thermostat. A/C seemed to kick in normally, but all that came out of the vents was warm air. I even waited a few minutes thinking it was just the residual warm air in the ducts. Any ideas of what went wrong??

Thanks!

Comments (13)

  • mike_home
    12 years ago

    Below is a link which may help you.

    Do you have a heat pump? An orange wire is usually the reversing valve for a heat pump. Connecting it to the W terminal is not going to work.

    If you do have a heat pump, then check to see if your thermostat is compatible.

    Here is a link that might be useful: Thermostat wiring

  • cujosocal
    Original Author
    12 years ago

    How can I tell if I have a heat pump? We're renting a duplex in AZ. The entire unit is on the roof...

  • weedmeister
    12 years ago

    what colors were connected to which screws on the old thermostat?

    Red is power, Green is Fan, Yellow is 'turn on compressor' (for a heat pump, anyway), White is heat. There will be another wire for the reversing valve for a heat pump. Which probably doesn't matter since the Hunter 44110 doesn't support a heat pump.

  • cujosocal
    Original Author
    12 years ago

    The old thermostat had exactly the same colored terminals as the wires... R,Y,G,O

    I doubt I have a heat pump. The house is all electric.

  • mike_home
    12 years ago

    If the unit is all electric, then it is highly likely you have a heat pump. The other possibilites would be an electric furnace or resistance baseboard heat.

    Do you have the model number of the old thermostat? If yes, then do a Google search and see if it is compatible with a heat pump. If it is, you need to exchange the Hunter 44110 for another model.

  • cujosocal
    Original Author
    12 years ago

    I can't find a manufacture label on the unit... I think it was taken off and the service company put their own tag on it.

    Assuming I do have a heat pump. Would it make sense to only have these 4 wires (and no white) mentioned for both heating and cooling??

  • mike_home
    12 years ago

    For everything I have read, yes it makes sense that the orange wire replaces the white wire for a heat pump configuration.

    The white wire is used to turn on the furnace for heat, and the yellow wire enables the condenser for cooling. But you have a heat pump, therefore when you are in heating mode, the thermostat will turn on the condenser (yellow), but it must also enable the reversing valve in the proper direction. The orange wire is used to control the reversing valve.

    Call the Hunter technical support line at 1-888-830-1326 from 8am to 5pm Central time. They should be able to review this with you and guide on which thermostat is appropriate for your set up.

  • weedmeister
    12 years ago

    Did the colored terminals on the old Tstat have labels? if so, what?

  • cujosocal
    Original Author
    12 years ago

    @weedmeister:

    Yes... as mentioned above "The old thermostat had exactly the same colored terminals as the wires... R,Y,G,O"... (colored terminals=labeling)

  • weedmeister
    12 years ago

    So the old tstat had an "O" and a "W", and the Orange was connected to "O"? Then, yes this is a heat pump thermostat and you need to go get a different one than that Hunter.

    Usually Heat Pumps also have Aux Heat. But you would probably never use it in Phoenix, and hence it may not be connected (W). Heat is activated by the reversing valve (O) which reverses the flow of the refrigerant through the system.

  • cujosocal
    Original Author
    12 years ago

    So it turns out I do have a heat pump! I exchanged my thermostat for one that supports a heat pump (3M Filtrete). It had connections for all 4 colored wires. Works perfectly!

    Thanks for all the help!

  • mike_home
    12 years ago

    I'm glad you got this resolved. Enjoy your new thermostat.

  • weedmeister
    12 years ago

    And thanks for coming back and reporting the outcome.