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Thread: Location of TXV

  1. #14
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    Quote Originally Posted by john_ertw View Post
    What will they be measuring (which temperatures and pressures) and what should it be set to?
    The proper superheat and subcooling numbers are located in your "Condensing Unit Installation Manual". Make sure the tech leaves this manual with you.

    For my TXV-equipped, R22, 14 SEER Goodman heat pump: superheat spec is 7 to 9 degrees, subcooling is 5 to 9 degrees. Not sure what it should be for your 410-A system.

    Superheat and subcooling are determined using pressure/temperature charts.

    Superheat = Suction line temperature - Saturated suction temperature.

    Suibcooling = Saturated liquid temp - Liquid line temp.

    Good luck.

  2. #15
    Join Date
    Aug 2008
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    Toronto, Ontario, Canada
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    The TXV was installed this evening. The tech explained that for suction lines upto 3/4" the bulb should go in either the 4 or 8 o'clock position while larger lines should have it installed in either the 10 or 2 o'clock position.

    The tech installed the bulb in the 4 o'clock position. After he left I looked over the installation instructions which only list 10 or 2 o'clock positions. Will there be any problems as installed.

    On a side note, the tech did not check superheat or subcooling. When I asked him to do so he explained that he did not have the required equipment with him. I questioned why he couldn't do it with the pressure gauges he was using earlier and he said he needed a special set that measures temperature as well. Is there any truth to this? I realized that I wasn't going to get anywhere so dropped it after that.

  3. #16
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    Quote Originally Posted by john_ertw View Post
    On a side note, the tech did not check superheat or subcooling. When I asked him to do so he explained that he did not have the required equipment with him. I questioned why he couldn't do it with the pressure gauges he was using earlier and he said he needed a special set that measures temperature as well. Is there any truth to this? I realized that I wasn't going to get anywhere so dropped it after that.
    Have him come back with the proper equipment to check, record, and adjust (if necessary) superheat and subcooling.

  4. #17
    Join Date
    Nov 2008
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    DFW,TX
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    yes he needs a manifold and a temp probe of some sort ,usually the one on his Meter would do, not sure how a tech does not have a meter that can check temperature.It is an important thing to set so this system will work in all situations at peak efficiency.

  5. #18
    Join Date
    Aug 2008
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    Toronto, Ontario, Canada
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    I have really changed my opinion on the contractor I ended up using. I dealt with the owner to get a quote and he worked with me to find the best solution in my situation (limited space required some creative thinking to install a media air filter and he ended up using a product that they never used in the past.. but then again I suggested the product).

    The installer was a really nice guy and really did know his stuff. He put 110% to ensure the installation looked good visually, but he did not put the same effort into commisssioning the equipment.

    I know believe that they purposely did not install the TXV to save on its cost. The installer said something to the effect that he has to put it in for long line sets (~ 45ft), but it’s a pain and doesn’t look nice so he likes to avoid it on shorter linesets (mine is in the 15 ft range). I bet not too many customers ever realize it isn’t there because most will not know what it is.

    As mentioned he did not check a/c pressures at all... just said that the charge in the unit is good for the length of pipe we have. I had to ask him to adjust blower speeds from the factory default and then he explained to me how to do it and recommeded to let it run for a few days at the default and then decide if I want to change it. When he came back to install the TXV, he said it was good that I lowered the a/c blower speed otherwise it would not dehumidify very well (I know DIY is not accepted here, but I wasn't going to leave the blower at 2000cfm with a 2.5 ton a/c). It would have taken him about 30 seconds to do this.

    I questioned the owner about not checking superheat and subcooling and he tried to make it sound like it wasn't a big deal and then mentioned that it was too cold to check anyways (it was only about 55 to 60F outside).

    I really don't know if I'll get anywhere trying to argue with them. I think the best thing may be to get another company in for a "service visit" and ensure that they check superheat and subcooling and adjust as required.

    I was recommending these guys to my parents and brother who are both in the market to change their entire systems this summer, but will tell them that I can no longer recommend this company.

    It's really sad because most consumers who use this company will see the clean install and their equipment will heat and cool so they will never question the quality of installation. There's a good chance the equipment may last 20 years without a problem, but on the other hand the installer did not do everything to ensure it was setup optimally.

  6. #19
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    Nov 2008
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    sorry to hear about your issues, i have found that a lot of large companys send out installers, most of which know how to install systems and get them turned on, however anything beyond that is really on a Real Technicians level of experience.I have seen these companys either ignore issues like this one or the better companys send a technician in,usually the one who sold the sytem or condemned it, to do the QC followup on the sytem and at that time they set all these specs as recommended by manufacturer.

    I myself do all my own work so i am there from start to finish as a small independent owner and the sevbice tech who then performs the installs.So i have full control and accountability to my systems and customers.

    A lot of big compnays bash the small one man shope but i can tell you this ,a ll my customers are happy when im done because i will always be there to adjust anything that may be needed to make them happy as promised at the point of sale.

    am i perfect, no ,but i am honest and reliable and will fix anything we have missed or comes up in the warranty period, that way i will get friends ,neighbors,and other referrals from this customer.

    this guy just lost two other sales because of something that would have took about 3 hrs max to adjust and make right..

    That is not a smart business decision IMO.

  7. #20
    Join Date
    Aug 2008
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    Toronto, Ontario, Canada
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    Quote Originally Posted by acguytx View Post
    this guy just lost two other sales because of something that would have took about 3 hrs max to adjust and make right..

    That is not a smart business decision IMO.
    It was actually 3 systems including a rental. They are all currently 19 to 25 years old so it seems to make sense to change them now with all of the government rebates.

    It is a small company... the owner organizes and schedules work and has one licensed tech with a helper to do the installs. They are fairly busy (need to schedule almost 2 weeks in advance) and it sounded like they would do everything necessary but that was not the case..

    The system may work for 25 years without a problem, but a little more work would have ensured everything was done properly and it would be less likely to have issues in the future.

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