Software
Houzz Logo Print
mrpandy

Help with thermostat wiring. please

7 years ago

I'm replacing a Honeywell T8011R with a Honeywell RTH9585 on my heat pump and I'm having trouble making the wires match up.

What I have:

  • G - green
  • C - black
  • R - red
  • W2 - brown
  • E - white
  • O - orange

Some of them make sense, but the various diagrams don't seem to be clear about what to do with the brown, white and orange wires.

Thanks for any assistance!

Comments (14)

  • 7 years ago

    You don't have a wire connected the "Y" terminal?

  • 7 years ago

    Nothing to Y, and W1 and Y are jumpered together with no wire on either. That's one of the mysteries since all of the diagrams I can find seem to use a Y wire.

  • 7 years ago

    If you trace the cable from the thermostat to the heat pump, how are terminals labeled?

  • 7 years ago

    This would make me wonder if it is not jumpered at the furnace, Y to W2. Or brown to Y.

    Are you sure there is no yellow wire?

  • 7 years ago

    Weedmeister makes a good point. Take a look at the connections at the air handler control board. I don't see how this works without the Y connection being energized. The heat pump does produce cool air in the summer, correct?

  • 7 years ago

    CALL HONEYWELL. Oops, sorry. Was I shouting? I had the same problem on a Sunday afternoon when all the local folks were closed. All I could get was heat no matter how I connected the wires. I called Honeywell and was disappointed at first to get a "girl" to help me. Of course I know that men and women are equally capable of reading manuals, and I hate it when stuff like that happens in my office. I guess I was caught by surprise indicating that I still have mental hurdles to work on. Anyway, 5 minutes or less later she got my wires uncrossed.

  • 7 years ago
    last modified: 7 years ago

    OK, so now you will see why I'm not an HVAC professional. I guess I took my stupid pills last night and didn't see that behind the unused blue wire, there actually is a yellow one on Y. Now I think all I need to do is go over the diagrams and figure out where the white (E) and brown (W2) go. One of the notes had them both going to W2-Aux/E but I'm going to read it all thoroughly before trying anything.

    This is especially embarrassing since I'm a technical writer and get paid to document things accurately. Thanks for all the replies.

  • 7 years ago

    Wouldn't hurt to look at the furnace to confirm the connections.

    If this is a 2-stage heating unit, W2 is for the 2nd stage. I would expect White to go on W1.

    E is usually for Emergency Heat, but also Auxiliary.

    There are standards for color matching, but sometimes they are not followed.

    If you have a single stage heating heat pump, then the combination of Y (compressor) and O (reversing valve) turns on the heat. W2 would be 2nd stage (if you have 2 stage) or auxiliary (the electrical heat strips). E would be for when you set the thermostat to Emergency manually, so sometimes it is jumpered to W2 and/or Aux.

  • 7 years ago

    It is a single stage heat pump. From the manual, it appears to me that i should do the following:

    • C - black
    • K - <none>
    • Rc - <none>
    • R - red
    • W-O/B - orange
    • Y - yellow
    • G - green
    • W2-Aux/E - brown & white
    • Y2 - <none>
    • L - <none>

    (there should also be a jumper loop between Rc and R since I don't have both Rc and R)


    Does anything look obviously wrong with this plan? Thanks again for helping this novice!

  • 7 years ago

    It would help to know what make/model heatpump you have.

  • 7 years ago

    If your thermostat has both R and Rc, then jumper them together.

    W and O/B are not the same thing usually. It may require a configuration change in the thermostat. W is for heat and O/B is for the reversing valve of a heat pump. It will either be positive for heat or positive for cooling depending on the heat pump vendor (Carrier does in one way, Trane the other).

  • 7 years ago

    I'm not home now to see any model numbers, but I know it's a Goodman single stage.

  • 11 days ago

    Did this work?

    • C - black
    • K - <none>
    • Rc - <none>
    • R - red
    • W-O/B - orange
    • Y - yellow
    • G - green
    • W2-Aux/E - brown & white
    • Y2 - <none>
    • L - <none>
  • 10 days ago

    Do you think this guy has been in a hot house in the summer and cold house in the winter for 7 years while waiting to get an answer?