Is it worth fixing pinhole on 25y old AC?

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Old 06-20-15, 10:57 PM
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Is it worth fixing pinhole on 25y old AC?

I have a 3 ton AC unit from about 1990 with a pinhole leak on the condenser U-Bend. Can it be fixed?
I read these can be braised, but I also read that it is not worth fixing such an old unit, because of the high cost of the refrigerant.

Is that true?

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The whole story:

Encouraged by the fact that I replaced the compressor fan on one of my parentís AC units two days ago (thanks to suggestions from this post! indeed), and having the whole operation of AC units demystified a bit from all the online info I read, I decided to look at what might be wrong with my parentís second AC unit which has not been operational for a long time.

My parentís house has two (3 ton, I believe) AC units. My parents tell me that when one of the units went out some years ago a repair person initially said it was the relay, but then later when he tried to fix it he said there was a leak and gave some expensive quote to fix it, at which point my parents resorted to using the other unit, which was enough for the most used rooms in the house anyway. At some later point, they called another repair person and he also said that the relay was bad and that there was also a pinhole leak on the condenser U-Bend which implied that it had been struck with some object (makes me wonder what that first guy did, but in any case itís been many years now).

So I took out the relay and managed to get it to work a bit, so now the compressor starts but there is no cooling at the vents, and no heating at the condenser. Hearing the history, I figured the system must be out of refrigerant, and looking around with a small mirror, I did indeed see the pinhole on one of the condenser U-bends and itís apparently the same hole the last repairman had pointed out. Anyway it is indeed a small round hole, indeed almost as if had been hit with a nail or tap or something.

So, anyway, here I am, wondering if itís worth fixing.

I probably wonít do this fix myself because even if I did manage to braise the pinhole (which seems to require hi temp torch which I donít have anyway) Iíd have to call someone to refill the refrigerant.

Any advice appreciated. Thanks.
 
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  #2  
Old 06-20-15, 11:07 PM
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It would be a bad gamble on a 1990 unit.

Refrigerant oil absorbs moisture. If it has been open to the atmosphere very long the compressor will probably die in less than a year after the repair.
 
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Old 06-20-15, 11:30 PM
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Well, Iím not sure what constitutes being open to air, but there is a detail I did not mention:

There is a small amount of some sort of glue on the pinhole. My dad tells me that someone suggested he at least close the hole when this all happened, perhaps exactly to prevent air from entering. Not sure what glue it is though, epoxy perhaps?
 
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Old 06-21-15, 01:14 AM
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I do my own A/C work & have the tooling , so I would try fixing it . Tooling is not cheap , but neither is paying an A/C tech .

First , I would change the Schrader valves on the service ports , as preventive maintenance . Install new ones , purchased at a refrigeration / A/C supply house . Coat them with refrigeration oil .

Install the caps on the service valves . Replace if necessary . I read the ones with an O-Ring inside are preferred .

I would take emery cloth and clean the spot of the leak , until it is bright shiny copper color . CLEAN .

Using Sil Fos 15 and a Pestolite I would braze / silver solder up the hole . I would braze / silver solder in a new dryer .


Now , you can call a tech to charge the system .

I have an EPA card & I have R22 . Which , as you said , is not cheap . Were it mine , I would continue to charge the system .

God bless
Wyr
 

Last edited by Houston204; 06-21-15 at 07:08 AM. Reason: Removed gauge readings.
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Old 06-21-15, 08:09 AM
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Thanks for the suggestions.

Is there a way to tell how much refrigerant it will take? I mean the system must be completely empty at this point, so it would have to be filled from 0 to capacity, I imagine. Then I can call and see how much they charge per pound and get some idea on what it may cost.

It's a Rheem unit, but I don't seem to be able to find the model. There are only some charging instructions inside that refer to pressures and lb per tubing to add, but I cannot see any references to total capacity.
 
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Old 06-21-15, 08:41 AM
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Not sure if it is worth to fix this 1990 AC. to fix it up, it will cost you more than $600. You may need 5-6lb of Freon (around $50/lb in my city), new dryer, new cap, plus 2 to 3 hours labor. (Assume everything else are still OK)
 
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Old 06-21-15, 01:52 PM
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If itís $600 it does not seem too bad.

Assuming a new unit costs us $4500 and lasts 20 years, that is $225 per year.
So, a $600 repair will have to last us about 2.5 years to break even.
A $1000 repair would then have to last 4.5 years.

Looks like I need to get some quotes before I can make a better assessment, as both the repair and replacement options seem viable at this point.

P.S. My parents can probably handle both scenarios from a cash flow standpoint, however, their glory days of earning income are gone, so they must be frugal to make a fixed amount last - hence my involvement.
 
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Old 06-21-15, 01:59 PM
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One thing to keep in mind. Most HVAC people say that the average life of a new A/C system is 10-15 years. While your old system lasted 25 years (my Bryant system is about 23 years old and still working), we have both been lucky. I'm not saying that you can't/won't get 25 years out of a new system, but in your cost/year calculations, you should probably figure on 10-15 years rather than 25.
 
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Old 06-21-15, 03:51 PM
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My concerns is ------ Are other components of the AC still in good shape ? It is hard to say for a 25 year old system, but you can take the $600 chance, and hope nothing else will break down in 2 years. So, get a couple of quotes first and go from there.
 
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Old 06-21-15, 09:20 PM
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I wouldn't recommend this gamble unless I could get a buddy or family price.
 
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Old 06-21-15, 11:25 PM
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Thomas, since you are going to do the calculation, it also depends on the weather of where you live too.

My central AC is about the same age, 1991. I have been contemplating whether to replace it or not for the last 7 years. I live in a state where it only gets hot 3 months out of the year. If I was living in Texas or Arizona, yeah, I would replace it since new central AC are also more efficient.

Anyway, I learned to improvised.
  • I have installed gable fans and garage fans for DRY HOT days.
  • I have installed window AC units for HUMID HOT days.
Both scenarios are so much cheaper to run than the central AC. In fact, the two window AC units that I bought paid for themselves in one summer. Why? We live in a 4 bedroom home. To run the central AC all night is not economical feasible when it is just my wife and I sleeping in one bedroom. New window AC units also have Dehumidifier mode built in and uses only a couple of amps vs central AC uses so much more amps.
 
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Old 06-22-15, 03:49 AM
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Should be a label stating the number of ounces the system requires + how much extra per foot for long line sets . This label may be long gone .

By the way , I just looked on line . I can buy a 30 pound cylinder of R22 for $ 308.00 . Wish we could charge almost 500% markup on material in our trade .

That is why I do my own HVAC . And , yes , I have an EPA card & can purchase refrigerant .

God bless
Wyr
 
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Old 07-06-15, 09:04 PM
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I'm wrestling with almost the same question, except it appears that our AC is closer to 30 years old. Have you considered using a sealant (i.e. Super Stop Leak, AC Stop Leak Plus)? If you already dealt with the problem, what did you decide?

Our HVAC tech says it will be more cost effective to get a new unit; however we don't use our central AC that often (less than two weeks out of a year), a new AC is not in our budget for this year, and we plan to move in about 5 years. So I am thinking about proposing using a sealant to get a couple more years out of the unit.
 
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Old 07-06-15, 09:31 PM
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I had a customer insist that I use a sealant on her leaking system. The delta tee dropped from 18 to 13 and the suction line went from 55 degrees to near freezing. ( it formed a restriction at the metering device)
 
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Old 07-07-15, 02:17 AM
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I have also heard the horror stories about sealants . I doubt I would use them , either .

God bless
Wyr
 
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Old 07-07-15, 08:18 AM
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Have you asked the AC tech to see if the unit can be repaired ($?).
 
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Old 07-07-15, 04:47 PM
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I have always believed (rightly or wrongly) that the worst thing for an Air Conditioner, Freezer, or Refrigerator is to let it sit for any extended period of time e copper without being used . . . . the copper becomes brittle and capillary leaks develop and the freon molecules will escape.

They should be run at least once a week just to re-seal the lines with the oils contained within the refrigerant.
 
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Old 07-07-15, 05:19 PM
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Originally Posted by Vermont
I have always believed (rightly or wrongly) that the worst thing for an Air Conditioner, Freezer, or Refrigerator is to let it sit for any extended period of time
I agree although I don't understand the science behind it. I noticed if I don't turn on my AC for an extended period of time, it has such a hard time cranking up. My relatives experience the same with their AC.
 
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Old 07-07-15, 05:25 PM
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I would avoid cranking up a condenser when it is 55 degrees outside.

Leaving a compressor off for the winter should be fine. Leaving a compressor off for years might be another matter.
 
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Old 07-08-15, 04:21 AM
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Especially , if it does not have a crank case heater . I have read the liquid refrigerant migrates to the crank case in cold weather and mixes with the oil ? The heater is suppose to evaporate the refrigerant out of the oil , I think .

God bless
Wyr
 
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