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heat pump wiring

i have always stayed away from heat pumps, but its time to stop being nervous.   i have a couple of questions if anyone will help me get through.  

  i installed one the other day and when called boss, got not to much help. 

  not realy sure on the sequence of operation?   t stat pro 6000   e,  aux , y, g, o, c. r, xl ,    air handler.  w1, w2, c, r, y, g, l,   cond.   w/66,  r, c, w2,    i hope i remembered them all.    my questions are when the cond is down or defrost the w/66 is the output  to turn on elec heat?.  in the air handler i jumped first and second stage of elec heat together. 

at tstat the o would be my heat pump  aux w1 and e w2?   i know this seems easy but  confusing me.  how does the t stat know when out door cond is in defrost?  is the e.  an input?  i know this isnt explaining myself to well.    but hope someone can direct me somewhere,   thanks  tom 


  • Ironman
    Ironman Member Posts: 7,379
    Let's State It as Simple as Possible

    At the thermostat

    R feeds the stat from the transformer. Everything switches from R.

    C is the other side from the transformer. Nothing switches from it. It's just there to make the logic and/or LEDs work.

    G = fan.

    Y = compressor in heating and cooling

    O = reversing valve. It's energized when stat's "system" switch is set to "cool".

    W or W2 = 2nd stage heat (usually electric elements).

    E = emergency heat. When "system" switch is turned to "EM HEAT" this becomes the first stage of heat and "Y" is disabled. Should be jumpered with "W" under normal conditions.

    The thermostat is not signalled by the heat pump when it goes into defrost. The defrost control simply energizes "O" to the reversing valve and de-energize the condenser fan motor.

    Also, be careful that you're reading the terminal identification from the "heat pump" markings, not the "conventional" markings. And be advised that Honeywell touch screen stat's have an "installer set up" that must be programmed to set the stat to the particular system on which it's installed. This must be done the installer (you) or the system will not function properly.

    Are you properly trained as to how you're supposed to leak test, evacuate and charge a heat pump during cold weather? The charge must be calculated and weighed in with an electronic scale. The charge that comes in the unit is not sufficient if there is more than 15 feet of line set. Please ask questions or get some help if you're unsure. Failure to do any of these correctly will eventually cause a compressor failure.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • ddlong1286@yahoo.com
    Read the Manual

    I am goin out on a limb here to say you have a York product, at least the outdoor unit(W66).

    I installed a couple of Luxaire 2 stage heat pumps last year and they have recommended wiring diagrams in the back of the installation manuals that correspond to recommended thermostats.

    That was a tremendous help to me!

    Somewhere the manual should state what the terminals do and/or mean.

    Don in MO
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