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Thread: Simple Question

  1. #1
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    Simple Question

    I have posted multiple times here. I live in an area where there are only 3 Heating and Cooling company's, very small town. All 3 have been out and all 3 have left saying everything was fine. My house is not old, my heat pump is a 4 ton unit, zoned, ugly pictures can be found in my other posts. I am getting very depressed. High electric bills, 120 KWh a day without even heating the basement. I just want to know why the temperature will decline 6 degrees after 6o seconds into startup. Is there anyone here that could give me a answer to this question.

  2. #2
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    Quote Originally Posted by carlb7 View Post
    I have posted multiple times here. I live in an area where there are only 3 Heating and Cooling company's, very small town. All 3 have been out and all 3 have left saying everything was fine. My house is not old, my heat pump is a 4 ton unit, zoned, ugly pictures can be found in my other posts. I am getting very depressed. High electric bills, 120 KWh a day without even heating the basement. I just want to know why the temperature will decline 6 degrees after 6o seconds into startup. Is there anyone here that could give me a answer to this question.
    This looks familiar but I do have bad short term memory.
    What temp and where?

  3. #3
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    Could be pulling cold air through wall cavity at stat.
    "Hey Lama, hey, how about a little something, you know, for the effort." And he says, "there won't be any money, but when you die, on your deathbed, you will receive total consciousness." So I got that goin' for me, which is nice. - Carl Spackler

  4. #4
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    The temperature is being read at the inside air handler. When I am outside watching the unit i see the accumulator frost up and the Scroll compressor starts making a louder noise. It is at this same time the temperature drops inside. The noise starts quieting down at the same time the temperature stops dropping inside. Then the pump works as it should. The efficiency of the heat pump has to be diminished therefore my power bill is taking the real heat.

  5. #5
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    So many variables...

    Is the unit sized correctly? What temps are you trying to maintain? Setback? Is ductwork correct for the unit?

    As an example, I was working on a heat pump split system that nobody could get to get WARM. It blew a motor bearing. Had the whole thing tore up and somebody mentioned the cold issue to me. Put it back together and took the time to diagnose a factory defect in the wiring.

    Unit had been installed for 10 years and the electric booster heat NEVER ran.

    Customer was never happy with the unit. Always were told that "It's a Heat Pump, that's how they work." It was in a child care area and they had to close when space temp went below 69 degress. Needless to say, they were closed almost all winter long until I found that.

    This is not to toot my horn as to how great I am, but to point out that oftentimes, assumptions are made by service techs, sometimes, even the best. Assume that the unit is sized correctly, that the dictwork is correct, that the home is insulated well, that the stat is calibrated correctly or set up correctly.

    If you are dissatisfied with the performance of the unit, then you need someone to analyze the ENTIRE situation, from top to bottom and side to side.

  6. #6
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    It's quite possible that on start-up your heat pump is in the partially in the cooling mode due to a faulty reversing valve and/or an improper charge.

    The frost and noisy compressor is due to liquid slugging since the system in partially or fully in the cooling mode until the differential pressures across the reversing valve are high enough to drive the valve in the fully heat mode direction.

    Then the system will start to produce heat.

    The only way a tech can catch this is to be there when it happens. First, all the basics must be check as to correct voltages to everything, correct refrigerant charge, correct air flow, etc.

    Then the tech should be able to catch the reversing valve at it's worst and find out why it's not transferring fully.

    Good Luck.
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

  7. #7
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    Quote Originally Posted by carlb7 View Post
    The temperature is being read at the inside air handler. When I am outside watching the unit i see the accumulator frost up and the Scroll compressor starts making a louder noise. It is at this same time the temperature drops inside. The noise starts quieting down at the same time the temperature stops dropping inside. Then the pump works as it should. The efficiency of the heat pump has to be diminished therefore my power bill is taking the real heat.
    As has been mentioned here before, there is a stabilization period that the unit must go through.

    What is the time period that these events unfold in? An hour or ten minutes?

  8. #8
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    Quote Originally Posted by carlb7 View Post
    I just want to know why the temperature will decline 6 degrees after 6o seconds into startup.

    Are you saying that when your indoor fan starts, the temperature on your thermostat declines 6 degrees in about a minute?? I just want to make sure I understand this....
    I need a new signature.....

  9. #9
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    Like delta said the rev. valve could be hanging up.

  10. #10
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    Are you saying that when your indoor fan starts, the temperature on your thermostat declines 6 degrees in about a minute??
    No, The air exiting the air handler.
    As has been mentioned here before, there is a stabilization period that the unit must go through.

    What is the time period that these events unfold in? An hour or ten minutes?
    After the first 60 seconds temperature starts falling. It takes about 4 to 5 minutes for the temperature to reach the temp that it began at. I went to another friends house to see if this was normal and their temp didn't drop a degree.
    It's quite possible that on start-up your heat pump is in the partially in the cooling mode due to a faulty reversing valve and/or an improper charge.
    How would the tech know it was the valve?

  11. #11
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    How is your return air run/located?

  12. #12
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    And are the temps from the vents or directly out of the air hand./er?

  13. #13
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    How is your return air run/located?
    It runs vertically straight up beside the unit to the first and second floors inside of a wall cavity.
    And are the temps from the vents or directly out of the air hand./er?
    Directly out of air handler.

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