Brand New Central Air System installed freezing up.

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Brand New Central Air System installed freezing up.

Postby kellogg49055 » Wed Jun 15, 2011 3:14 am

Ok, I have a 06 24X46 ft Double Wide mobile home. I got quotes from 3 different people who all quoted me a 2 ton (said that would be plenty for the size and setup of the house and how well it was insulated) and they quoted me between 2400-2800 for the complete installed.. I through a friend purchased a brand new 2.5 Ton 13seer with new A Coil and quick disconnect line set. Also purchased the base for it to sit on and the proper wire whip (harness) which they recommended. I even went as far as to replace the disconnect box which was on the house because it was setup for A/C and wired and the furnace was compatible because it was a little bent up and a new one was 6.00. This house was only lived in for 9 month's before my wife and I were lucky enough to purchase it clean and clear with no mortgage.Sunday a friend and I installed the unit. Then we wired it up and turned it on. it kicked on right away and then noticed the large line started to freeze over but only the line. It didnt start to freeze the evaporator coil or the condensor outside. The air inside seemed cooler but not cool enough. So I did some reading and I was told that sometimes the quick disconnect metal seals dont get punctured all the way. Yesterday I made sure ALL the lines were tight. so tight that i was afraid with 16" of leverage I was going to do some damage. All the connections started to tighten up, then got snug for second then got easy again so I assumed that it punctured the metal seals for the quick disconnect set. This was this way except for the inside large line at the a Coil. I tightened it up as tight as I could get it. Then I checked for leaks with a soapy solution with no leaks anywhere. Well today I started it back up and same thing with the line freezing. So I assumed it didnt puncture the seal so I grabbed my wrenchs and low and behold I tightened it 6
more turns and felt that hard then easy area like the rest and it tightened up on the threads just like the other 3 and as soon as this happened the frost on the line went away within seconds. The air was colder in the house by 10 degrees. Yesterday the air coming out of the register was 67 or so. Today after fixing the line it was 53. It worked fine untill this evening when it started to cool off outside. Then I felt hardly no air coming out of the vents and that line was frozen again. I looked inside the cabinent with a inspection coil and it was all iced over so thats why I had no air flow. Can anyone tell me why it's freezing over? is it because it cooled off outside? even though I didnt hear any leaks and my soapy solution didnt show any, is there a chance it's low on Freon? I just want it right. I called the company I bought it from and they said it's low on Freon, i'm not arguing but they are rediculous in price so if there are any other ideas I sure would listien and investigate. Thank you in advance. It's just when you pay so much for something you want it right.
kellogg49055
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- Brand New Central Air System installed freezing up.

Postby nomadpeo » Wed Jun 15, 2011 7:53 am

i didn't hear anything about a liquid line filter, gauges or vacuum pump. so you guys just connected the lines and turned it on. no system is that 'plug-n-play'. standard service procedures need to be followed and that's why it needs to be done by a professional. it probably is still low on freon, but it also needs to have a liquid line filter/drier in the small line. it could already be installed in the outside unit. if the lines are precharged with refrigerant and there is a drier already installed, maybe a vacuum wouldn't be required, but i'm skeptical. in any case, the final charge needs to be determined by technical means utilizing a strap on thermometer and pressure gauges. if you do not have instrumentation, you are still going to need to hire someone to balance it.
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- Brand New Central Air System installed freezing up.

Postby kellogg49055 » Wed Jun 15, 2011 2:19 pm

Ok, then I will hire someone to come check it out. But it was sold to me as a plug and play. the condensor, lines and coil were prechared and had like metal disk's sealing them and then when you tighten them they ruptured the disc releasing the Freon into the entire system. There looks to be a dryer inside the main condensor unit but there isnt one onthe line. I have experience of 10 yrs and am licensed as far as Auto and RV AC Repair but not home and I just followed directions and then checked for leaks. Thanks for the response.
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- Brand New Central Air System installed freezing up.

Postby nomadpeo » Thu Jun 16, 2011 7:16 am

it's been many years since i installed one of those precharged lines on a mobile home, but i think that's right. the piercing device should allow the refrigerant to be released from the cu and into the evap. if there is a filter/drier in the cu, you should be ok. depending upon the length of the line, you may be undercharged. measure the suction line and compare it to the evap temp (from the gauge). this superheat calculation needs to be within acceptable range (5 -20 ; cooler temp outside results in higher superheat). if superheat is too high, add freon.

mobile homes typically need a bump in tonnage due to the inherent heat gain. that half ton difference probably is not a problem.

didn't know you were an industry professional. no disrespect intended. let us know what your pressures and superheat turns out to be. be sure to check your delta t (return air - supply air).
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