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Thread: HP modes?

  1. #1
    Join Date
    May 2005
    Posts
    15
    I am installing a Carrier yra38 which is a single stage heat pump. I am noticing that in the outdoor unit there is a white W1 wire that the literature states is to be used for second stage heating.

    Does anybody know how this single stage outdoor unit operates differently when this signal is active as opposed to operation when in the normal first stage heating mode (i.e., reversing valve in the heat position).

    Thanks!


  2. #2
    Join Date
    Feb 2004
    Posts
    2,597
    it's for defrost mode, cycles the electric strips.

  3. #3
    Join Date
    May 2005
    Posts
    15
    Ah ... Thanks Bill!

    I don't have any supplemental/electric heat in the air handler - it's a Carrier FK4D BTW. Can I assume that the FK4D is smart enough to not run the fan in the defrost mode if no electric heat is installed, or must I live with it blowing cold air when the HP is in the defrost mode.

    Thanks again Bill

  4. #4
    Join Date
    Nov 2004
    Posts
    2,927
    I am guessing it goes to accumulated run time on the defrost board.It will need fan as far I know,and yes it will blow cold air.

    Sometimes there are compounding complexities of multiple variables that are not intuitively obvious

  5. #5
    Join Date
    Dec 2004
    Posts
    201
    you could use the w1 from out door unit to energize a relay that would break power to blower. DO NOT DO THIS IT WILL DAMAGE YOUR SYSTEM!

    [Edited by filterchanger on 07-31-2005 at 08:28 PM]

  6. #6
    Join Date
    May 2005
    Posts
    15
    Sounds like a good idea.

    However, now I am wondering whether the indoor coil would freeze up without the blower on in defrost. The heat to defrost the outdoor coils must come from somewhere. When you come out of defrost you would still get cool air until the indoor coil warms up unless you delayed the blower fan coming on. This is getting a little complicated - I guess I should have opted for a small electric heat strip.

  7. #7
    Join Date
    Jul 2005
    Posts
    7
    Where did you buy your heatpump? E-bay?

  8. #8
    if you kill the indoor fan douring deforest the outdoor unit will not deforst right you will also send liquid back to the compresor blowing it
    you will also frezze up the inside coil
    you will need to get back up heat or just deal with the cold air

    just do it right in the first place please

  9. #9
    Join Date
    Dec 2004
    Posts
    201
    Robert is right. I didnt think anyone would take me serious. Ill be carefull in the future, sorry bout that!

  10. #10
    Join Date
    May 2005
    Posts
    15
    pugdog - I looked long and hard to find a system I wanted; however, I can't divuldge my source for fear of getting him in trouble. If you look hard enough you can find Carrier/Bryant equipment. Goodman and the like are easy to find. It turns out that the HVAC industry is fairly tightly controlled for some reason (this website not withstanding).


  11. #11
    Join Date
    May 2005
    Posts
    15
    filterchanger - as a homeowner this is my first system I have ever installed. I would have gladly paid somebody to do it but couldn't find anyone who would even give me a bid on my retrofit job which included ductwork.

    By the way - when I was trying to get bids on this job a few contractors laughed when I asked about supplemental electric heat as it rarely gets below 40 where I live. It looks like good HVAC people are hard to find in my area ...

    I thought the following topic today by wideawake was rather telling - or was that sarcasm also??

    http://hvac-talk.com/vbb/showthread.php?threadid=81407

  12. #12
    Join Date
    Jan 2004
    Location
    PA
    Posts
    68,776
    Find it hard to beleive no contractor wanted to give you a bid.

    But it does happen.

    You may not need strip heaters if the temp doesn't get below 40.

    BUT, you do need the blower to run during defrost.

    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

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