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Thread: 3rd Carrier TXV

  1. #1

    3rd Carrier TXV

    Contractor wants to install a fourth TXV on a new system.

    I purchased a new Carrier heat pump (25HPA524 and FV4BNF003) at the beginning of the summer. This replaced a comfort series Carrier of the same tonnage. A week or so after the install, the unit had a hard time keeping up. The contractor came out and said the compressor shut off and reset it. He said if it happens again they would replace the TXV because the pressure is too high.

    After that I noticed that the system had a hard time keeping up even when the outdoor temperature was in the 80's. We live in the Washington DC area. Thermostat was set at 72 but the indoor temp crept to 74 and sometimes 76. The outdoor fan would run all day even in mild whether and only shut off sometime in the middle of the night until early morning. The contractor replaced the TXV. After that I noticed that the outdoor unit would sometimes have a loud sound and then a low sound. When the sound is high the air coming from the unit fan is hotter than the air outside. When the outdoor unit is quiter the air coming from the fan is the same as the outside air temp. The contractor then replaced the thermostat (TSTATCCPRH01) but the problem still occurred.

    The owner of the company (which has a good reprutiation) came out with one of his men and took some measurements and went over the whole system. They concluded that it was another faulty TXV. They replaced it again. The problem still seems to ocur.

    The contractor claims that it is yet another faulty TXV. He says they are hit or miss. He has done several new installs some have no problem at all while others they had to replace the TXV several times. He says that when the unit is quite and blows the same temp as the air outside temp the compressor has shut downs due to too much pressure. When the air coming from the unit fan is hot the compressor is running. He wants to replace the TXV again.

    All work is under warranty. What do you guys think?

  2. #2
    Join Date
    Aug 2007
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    Northern VA 38 degrees N by 76 degrees W
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    I would have someone else look at it. Did he leave you service tickets with pressures and temperatures supply and return, super heat and sub cooling, and wet bulb, and compressor amperage, CFM. With this information it will clear up a lot of speculation and guessing. if you have this information post it. If the dealer did not provide it seek another dealer. Where are you located?

  3. #3
    Prior to replacing the last TXV, I had the following readings (not sure what they mean): 285/129 at 83 degrees; subcooling 11 degrees; liquid line temp 83 degrees; suction temp 52 degrees; fanspeed up all the way; amps ok comp. 5.9 fan 0.5









    Quote Originally Posted by second opinion View Post
    I would have someone else look at it. Did he leave you service tickets with pressures and temperatures supply and return, super heat and sub cooling, and wet bulb, and compressor amperage, CFM. With this information it will clear up a lot of speculation and guessing. if you have this information post it. If the dealer did not provide it seek another dealer. Where are you located?

  4. #4
    That contractor does not know what he is doing other than changing out the txv until the problem finally is the txv.

  5. #5
    Join Date
    Nov 2000
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    Then again, there have been several txv manufacturing issues over the past couple of years.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  6. #6
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    Office and warehouse in both Crystal River & New Port Richey ,FL
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    What is the serial number of the outdoor unit???

  7. #7
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    Quote Originally Posted by dash View Post
    What is the serial number of the outdoor unit???
    Duh!!! This is the first question we should have asked.

    With scroll compressors so prevelent now days, we tend to forget about start components. Then again, even scrolls need a little boost once in a while. Good catch.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  8. #8
    Join Date
    Nov 2003
    Location
    katy texas
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    157

    5-2-1= Bohica !

    521 = common , start and run .
    The system needs starting components , also request that the system have the refrigerant reclaimed , dryer replaced , evacuated to 400 microns ( verified with digital technology ) and re-charged with virgin refrigerant .do not pay for any of this unless you like BOHICA

  9. #9
    Join Date
    Jun 2007
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    Round Rock
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    3,623
    You might have some trash in the lineset. The installers might have gotten sloppy covering the copper when they cut it. I would blow it out with nitrogen and put the filter drier right at the evaporator coil, just in case. I've had a rash of bad TXV's lately. But never 4 on the same unit.

  10. #10
    Join Date
    Jul 2008
    Posts
    53
    From the pressure/temp you gave it looks like this is an R410A system. 11 degrees F subcooling and 7 degrees F superheat doesn't sound like a bad TXV. Most systems are looking for 10-12 degrees F subcooling and 10-12 degrees F superheat when using a TXV. Indoor temperature, outdoor temperature impact this a great deal as well. The fan speed being on high is ok, but what is the actual airflow? If they have not determined that the correct CFM (cubic feet per minute) is being provided, the rest of the measurements mean nothing.

  11. #11
    Join Date
    Mar 2008
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    i'm not familiar carrier equipment but could it be a 2 stage HP only wired for single stage, therefore running at only roughly 60 % capacity..........yes i know its a shot in the dark.
    "The things you own end up owning you. "

    Tyler Durden

  12. #12
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    Quote Originally Posted by badboyheel View Post
    i'm not familiar carrier equipment but could it be a 2 stage HP only wired for single stage, therefore running at only roughly 60 % capacity..........yes i know its a shot in the dark.
    Single stage,but the air handler has about 20 steps to go thru to configure operation,so there could easily be an airfow issue.

  13. #13
    Join Date
    Mar 2008
    Posts
    657
    in that case, like you said, blower set up would be a good place to start
    "The things you own end up owning you. "

    Tyler Durden

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