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-   -   Installation of programmable thermostat (https://www.askmehelpdesk.com/showthread.php?t=413457)

  • Nov 6, 2009, 07:32 PM
    didiathome
    Installation of programmable thermostat
    I've just bought a new programmable thermostat. In the installation guide, it says "The wires are usually designated W, Y, G, RH, RC, O, B, H1, H2."
    But, in mine, a Coleman system, they are designated as W2, Y, G, O, B, L, E, X, R. How should I make them match?
    Thanks!
  • Nov 6, 2009, 07:47 PM
    Joshdta

    Are there more terminals on the new stat other then the ones you have listed?
  • Nov 6, 2009, 07:48 PM
    didiathome
    Nope, that's all I have
  • Nov 6, 2009, 07:51 PM
    Joshdta

    What does the instructions say the h1, and h2 are for?
  • Nov 6, 2009, 07:54 PM
    didiathome
    H1 and H2 are for an humidifier... But, I don't think my system is equipped with an humidifier
  • Nov 6, 2009, 07:57 PM
    Joshdta

    Does this new stat say it will work for 2 heat 1 cool? Or just 1 heat 1 cool with heatpump?
  • Nov 6, 2009, 08:05 PM
    didiathome
    It says:
    - automatic heating or air conditioning control
    - for central heating systems
    - 5+1+1 day programmable thermostat
  • Nov 6, 2009, 08:08 PM
    Joshdta

    Inless it says 2 heat it will probably not work for you. You will have to get a 2 heat stat to get your electric furnace and heatpump to both work
  • Nov 6, 2009, 08:12 PM
    didiathome
    Ok, so I will put everything back in the box and go back to the store!
  • Nov 6, 2009, 08:25 PM
    KISS

    Your new stat doesn't have the ability to set the furnace to Emergency Heat - The E terminal is missing

    X is probably (C) or common which is sometimes used. Not used if the thermostat is powered by batteries alone.

    L is an indicator - has various uses, not needed.

    Ususllay you have O/B not O and B. SOme zoning controls require both. It's rare to find them. You generally program how O/B behaves. It usually goes to the reversing valve.

    On the new stat Rc gets conncted to Rh and it becomes R.
    H1 and H2 is a dry contact for a humidifier.

    W could connect to W2


    Biggest problem your missing E. E forces the heat pump off and uses the strip heaters alone. Make sure you need both O & B.

    Wrong stat. You need one with Emergency heat.
  • Nov 12, 2009, 04:17 PM
    didiathome
    I finally bought a new thermostat that should be oki. But I still have one last problem:

    Wires existing on my old system : W2 ; Y ; G ; O ; B ; L ; E ; X ; R
    Wiring suggested: W2 - Aux ; Y - Y ; G - G ; O - O/B ; B - C ; L - L ; E - E ; X - (C or E, already used!); R - R
    So, I have a problem with my X!
    The only other plugs available are RC and Y2.

    "KeepItSimpleStupid" wrote : "X is probably (C) or common which is sometimes used. Not used if the thermostat is powered by batteries alone."

    - That means that if I use batteries, I can use just without wiring it?

    Thanks!
  • Nov 12, 2009, 05:20 PM
    KISS

    Yep. Is your unit a Trane by chance?

    You also need to jumper Rc to R and possibly Y2 to Y on the thermostat. Rc to R is a necessity, otherwise the fan and AC won't work.
  • Nov 13, 2009, 07:02 AM
    didiathome
    My new thermostat is a Honeywell.

    The jumper between Rc and R is already there, but not between y2 and y and there is no mention about it in the instructions.
  • Nov 13, 2009, 08:02 AM
    KISS

    You didn't mention the model of the thermostat. Y2 is second stage cool. If you can set the tsat to 1 stage cooling, that would be best.

    I believe Y2, unconnected will be fine.

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