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    jasonjaj26's Avatar
    jasonjaj26 Posts: 7, Reputation: 1
    New Member
     
    #1

    Feb 19, 2009, 06:16 AM
    trying to figure out honeywell rth7400
    Ok I have way too much info to confuse someone so here we go.
    I have an old amana therm. Not sure which numbers are the model number so I'll list them all.
    (Q674F 1022)
    (T874C 1059)
    class 2 30V max LR1620
    here is how it was wired

    brown---x2 out side went to 2 browns one to defrost board and one to heater coils

    white---w1> out side white and yellow together wire to a yellow that goes to defrost board
    yellow--y1> " " " " "

    blue---w2 out side goes to 2 whites & a purple. 1 white an purple goes to heat strips and other white goes to defrost board.

    green---g out side green goes to fan relay

    red---r out side red goes to defrost board

    orange---o out side orange goes to defrost board

    new therm. Is honeywell RTH7400
    options are

    C
    G
    Y
    O/B
    RC JUMPED WITH R
    AUX
    E
    L

    I wired it they way I thought it would work and it seemed like the a/c worked fine
    but it didn't want to work with heater ?

    the way I did was
    C=BLUE
    G=GREEN
    Y=YELLOW
    O/B=ORANGE
    R=RED
    AUX=BROWN
    E=WHITE

    THIS IS THE PAYNE UNIT I HAVE OUTSIDE http://www.docs.hvacpartners.com/idc...im-ph1z-03.pdf
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #2

    Feb 19, 2009, 06:36 AM
    https://www.askmehelpdesk.com/heatin...ll-314622.html

    This might help you out some
    jasonjaj26's Avatar
    jasonjaj26 Posts: 7, Reputation: 1
    New Member
     
    #3

    Feb 19, 2009, 06:52 AM
    That was my previous post before I found out that the wires to the back of the thermostat wasn't going straight to the heat pump. Apparently when the old outside unit was replaced they just spliced some wires together to make it work some of the wires that are on the old therm. Aren't even hooked up outside. Now I'm left to try and figure out what they did. That's why I need someone to look at the information I have gathered so far and tell me what color wire needs to go to which letter on the back of the new thermostat
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #4

    Feb 19, 2009, 07:41 AM
    You will need to post the Exact color to Exactly where that wire goes on the equipment. Then the thermostat might be able to be figured out.
    jasonjaj26's Avatar
    jasonjaj26 Posts: 7, Reputation: 1
    New Member
     
    #5

    Feb 19, 2009, 07:44 AM
    brown---x2 out side went to 2 browns one to defrost board and one to heater coils

    white---w1> out side white and yellow together wire to a yellow that goes to defrost board
    yellow--y1> " " " " "

    blue---w2 out side goes to 2 whites & a purple. 1 white an purple goes to heat strips and other white goes to defrost board.

    green---g out side green goes to fan relay

    red---r out side red goes to defrost board

    orange---o out side orange goes to defrost board
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #6

    Feb 19, 2009, 09:20 AM
    Take a look at this change over sheet. It should cover just about all the situations in combination with the diagram of the unit you provided and the new thermostat wiring diagram.
    Attached Images
  1. File Type: pdf heat pump wiring.pdf (13.3 KB, 124 views)
  2. hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #7

    Feb 19, 2009, 09:22 AM
    Note you will also have to run the setup on the new thermostat so that O is used for defrost.
    jasonjaj26's Avatar
    jasonjaj26 Posts: 7, Reputation: 1
    New Member
     
    #8

    Feb 19, 2009, 10:13 AM
    Thanks that helps a good bit. The only two that I can't seem to figure out is which color white or brown should go to emer.heat (e)and then I guess the other would go to aux. heat (w2) how do I find out which one (white or brown) goes to emerg. Heat and which one goes to Aux. heat?
    Mikie D's Avatar
    Mikie D Posts: 45, Reputation: 1
    Junior Member
     
    #9

    Mar 13, 2009, 05:25 PM

    Put the white wire on aux heat and see if reversing valve denergizes so it goes into heat pump mode or vise versa see if the electric heat back up pulls in it can only be one or the other especially if a/c works but normally A/C only kicks in when reversing valve is energized.Mikie D

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