ReplyDepending on the coil. It fits in very easily.
Regular Guest
I'm wondering where the TXV is normally installed? I had my new furnace and a/c installed yesterday and realized that I did not see a TXV when I looked over the system after the installer left.
I called this morning and was told it was installed inside the ductwork with the uncased coil to look cleaner and protect the valve. Is it possible for it to fit there? How much space does it take? From photos of TXV's I can't imagine it can fit inside the plenum.
God Speed, Jim. We'll miss you - 2-26-23
Depending on the coil. It fits in very easily.
Professional Member
most residential TXV's are half the size of your fist or smaller.
Regular Guest
Good to know that it can fit inside. I will take a closer look tonight when I get home. I was a little concerned because I was left all documentation that came with all of the other components I purchased, but did not receive anything for the TXV such as the installation sheets. Also I did not see the actual TXV with the other equipment when it was brought into the house (although I could have missed it due to its small size).
Professional Member*
they can be eithr inside or outside,most newer coils they come installed in the coil from manufacturer but other brands stll leave the option to you so they are field installed by the technician.so yes your is most likely there but you cant see it.
Global Moderator
Model # of the coil or at least brand?
Professional Member
relax, it will be fine it is standard practice.
Regular Guest
It's a Goodman CAUF3743C6A uncased coil. I was able to remove the seal around the suction line which left just enough space to look at the lines inside the plenum.
You ask "What did you see?"
There was no TXV. The line's factory fitting was right against the plenum sheet metal and no bulb was attached to the suction line.
I believe it was an honest mistake. I called the contractor (I have always talked with the owner, not the installer) and he talked to the installer to confirm. Somehow it got missed. I believe it was a mistake because I was asking the installer about how a TXV works and what the benefits are early in the day and he said it's good that I'm putting one in after explaining it to me.
So moral of the story...
Not so. A questioning attitude allowed me to find a mistake with my installation that would not have been found if I assumed all techs to be perfect.relax, it will be fine it is standard practice
To be fair I was impressed with my tech except for this one screw up which you can consider to be a big one. He took his time to ensure every step was well thought out before completing and communicated very well with his assistant to ensure his assistant did not miss any steps.
Professional Member*
If there was no TXV, then was there any metering device installed at all??? Maybe the tech is used to installing cased coils which usually have the TXV pre-installed form the factory.
Regular Guest
I believe a checkstyle flowrater was installed in the coil at the factory. I believe it was an honest mistake.
I want to make sure the tech installs the TXV properly and does not need to come back.
I was told the tech will remove the refrigerant, install the TXV, evacuate the lines, and charge the system. Is anything missing or incorrect?
My contractor said they may put all of the refrigerant back into the condensing unit so that it is in the same state as a new unit in order for the tech to install the TXV. Can this be done and is it a good idea?
My understanding is that after the TXV is installed and the system is evacuated, the refrigerant should be release back into the system and it should be setup using subcooling and superheat. Is this correct? Is there any other way to ensure the charge is correct? How can I tell if the tech is doing this part properly? What will they be measuring (which temperatures and pressures) and what should it be set to? Is it normal to have to add or remove refrigerant when installing a new system or is the refrigerant included with the compressor usually adequate?
Sorry for the number of questions, but I only want the tech to make one visit to correct the problem properly.
Professional Member*
What is the model number on your outside unit? Once the freon is pumped into the outside unit, the TXV can be installed, however the tech should still check operation, and subcooling to make sure none was lost. Also make sure they leak check joints around the TXV. If you had a 13 SEER unit installed, the flowrater will deliver 13, but not any higher SEERs.
Regular Guest
Outside unit: 2.5 ton Goodman SSX140301
Inside coil: CAUF3743D6A
How should the tech leak check joints around the TXV?
How does tech check subcooling? Is this what is being done when attaching gauges on the outside unit?
God Speed, Jim. We'll miss you - 2-26-23
With a leak detector.
With guages and thermoprobes.
Regular Guest
The proper superheat and subcooling numbers are located in your "Condensing Unit Installation Manual". Make sure the tech leaves this manual with you.Originally Posted by john_ertw
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.
Regular Guest
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.
Regular Guest
Have him come back with the proper equipment to check, record, and adjust (if necessary) superheat and subcooling.
Professional Member*
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.
Regular Guest
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.
Professional Member*
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.
Regular Guest
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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