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Central AC help needed

Old 07-08-2015, 04:23 AM
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Default Central AC help needed

Had an expensive weekend. Turned the AC on for the first time and nothing but warm air came out. Asked a neighbor for a referral and the guy came out in the afternoon. He put the gauge's on and said there was no freon in the system. He pressurized the system with nitrogen for a few minutes and it held pressure so he put a vacuum on it for 20 minutes then filled the system with R22. He pumped 5lbs of freon in which filled the system completely and the AC was blowing cold air. At the 12hr mark or just there after I noticed the temp in the house was 3 degrees warmer then the thermostat was set for. Checked the air at the register and warm air was blowing out. So I got a little over 12hrs of AC for $500. Question how hard is it to a find a leak when almost 5lbs of freon gets dumped in 12hrs.
Its a Coleman 3 ton unit. And on a side note I thought I heard an air leak when he put the nitrogen on but the noise stopped when more pressure was added. At this time the guy said he was going to lock down the system to see which part has the leak but haven't heard anything in a couple of days
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Old 07-08-2015, 04:26 AM
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Its leaking, gotta find the leak thats probally on the linesets.
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Old 07-08-2015, 04:35 AM
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First thing I would do is call the guy that recharged the system and demand he find and fix the leak on his dime. It is most likely on the low pressure side of the system as a leak that size would normally be visible on the high side by leaking oil as well as refrigerant.

This same guy knowingly added refrigerant to a system that was leaking without repairing any leaks. He has assumed a good bit of liability in just doing that.

R-22 is being phased out and getting very expensive. If your unit is of some age it may be time to think about replacing it with a 410 A system especially if your evaporator coil is leaking of which I suspect.

As a side note he did not accomplish a proper evacuation on a system with leak. You now have non-condensibles "air " AND MOISTURE IN YOUR SYSTEM.
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Old 07-08-2015, 04:42 AM
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Originally Posted by 20biminitwist View Post
First thing I would do is call the guy that recharged the system and demand he find and fix the leak on his dime. It is most likely on the low pressure side of the system as a leak that size would normally be visible on the high side by leaking oil as well as refrigerant.

This same guy knowingly added refrigerant to a system that was leaking without repairing any leaks. He has assumed a good bit of liability in just doing that.

R-22 is being phased out and getting very expensive. If your unit is of some age it may be time to think about replacing it with a 410 A system especially if your evaporator coil is leaking of which I suspect.
So far he is doing the leak testing on his dime or mine since the freon was $60. dollars a lb. and you can buy 30lbs for about $400. delivered. I knew there was a leak because we had the system recharged several years ago for $180. Due to storm damage the house has been unusable until now so I don't know how long that charge lasted. I just have a hard time believing that a leak of that size would be hard to find.

Last edited by Mine Now; 07-08-2015 at 05:05 AM.
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Old 07-08-2015, 04:54 AM
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If it's a split system the location of the Air handler can sometimes limit access to the evap coil. That is why I suspect it as being the culprit. A good electronic leak detector should at least be able to sniff out a leak that size to the point as to identify general location. If the leak is in the evap tubing it will most likely be hard to pin point and will be basically unrepairable.
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Old 07-08-2015, 05:10 AM
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He went up to the air handler to listen for a leak but didn't hear anything . I don't know if he has an electronic sniffer or not, Ill have to ask. All he can do now is lock up the system from the outside because no one is at the house to give him access to the inside. He should be able to at least tell if the leak is outside or inside, correct?
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Old 07-08-2015, 05:23 AM
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If the unit has isolation valves he can isolate the high side from the low side and determine which side of the system is leaking.

That size leak should be easy to find with soap bubbles unless it's in the coil tubing.

I find it strange for a service tech to not have some type of electronic leak detection instrument. The good ole uncle Sam has some fairly stiff penalties for venting refrigerant.

I work on primarily large commercial and industrial size equipment holding hundreds of pounds of refrigerant and we are closely watched on our refrigerant usage.
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Old 07-08-2015, 05:44 AM
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Originally Posted by Mine Now View Post
He went up to the air handler to listen for a leak but didn't hear anything . I don't know if he has an electronic sniffer or not, Ill have to ask. All he can do now is lock up the system from the outside because no one is at the house to give him access to the inside. He should be able to at least tell if the leak is outside or inside, correct?
Is he a REAL a/c tech?

Sometimes the leak is at the schrader valve where it fills. My experience, it's either the evaporator coil or leaky schrader.
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Old 07-08-2015, 05:47 AM
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If remodeling was done to repair the damage it is not uncommon to have a puncture from a trim nail or screw. Wall cavity leaks can be a bitch to find. Our guy found ours with a stethoscope that was home made.

$275 for two trips and repair/recharge is all I paid. Long standing family business in MA.
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Old 07-08-2015, 01:11 PM
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[quote=20biminitwist;8027987]

This same guy knowingly added refrigerant to a system that was leaking without repairing any leaks. He has assumed a good bit of liability in just doing that.]

funny you would say that, a buddy of mine had a new 2 stage unit installed and from year 1, 2 times a year the htg a/c guy came back and added freon, that story did not have a happy ending

any A/c guy that would add freon more than once without finding the leak needs the boot!
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Old 07-08-2015, 04:11 PM
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Originally Posted by billinstuart View Post
Is he a REAL a/c tech?

Sometimes the leak is at the schrader valve where it fills. My experience, it's either the evaporator coil or leaky schrader.
My neighbor said that his family has been using this company ( father and son ) for 30 yrs.
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Old 07-08-2015, 04:16 PM
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Originally Posted by BACKTOTHESEA View Post
If remodeling was done to repair the damage it is not uncommon to have a puncture from a trim nail or screw. Wall cavity leaks can be a bitch to find. Our guy found ours with a stethoscope that was home made.

$275 for two trips and repair/recharge is all I paid. Long standing family business in MA.
None of the work that was done came close to the AC system.
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Old 07-08-2015, 06:47 PM
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That's an extremely fast leak and a tech with a 1/4 brain should be able to find that size leak in 30 minutes or so.


A leak that fast will be able to be heard with your ears if the system is pressurized to around 100 psi.

------------------------------------------------------------------------

If there wasn't an oil spot around the outdoor unit then pressurize the system, pop the cover to the evaporator, and have a listen.

It's in 1 of 3 places. Indoor coil, outdoor coil, or lineset. Unless this is a package unit in which case the tech was just very lazy. Sometimes lineset leaks are hard to find if you can't get to the whole length of it.
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Old 07-08-2015, 07:48 PM
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Unfortunately good help is hard to come by for most companies these days. A lot of companies are forced to keep bad techs because of the work load. Ask me how I know...
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Old 07-08-2015, 07:53 PM
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Fwiw the last leak I found that was empty in a couple of days was in the condenser on a factory copper joint near the edge of the coil. Another company had already robbed this woman of 600$ TWICE! And told her the leak was underground.
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Old 07-08-2015, 08:24 PM
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funny stuff here
Do any of you posting actually have a license to purchase refrigerant.

The OP states he can buy online and have it delivered?

Can you guys where ever actually purchase refrigerant without owning a recovery machine or a certificate from the EPA.

if no recovery machine how do you change a compressor or break into a charged system without venting?

back to the OP. If the unit is of age and has a leaking coil, get rid of it. The drop in gas for R-22 is not worth the hassle for an alternative.
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Old 07-09-2015, 03:01 AM
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Originally Posted by baypro21 View Post
That's an extremely fast leak and a tech with a 1/4 brain should be able to find that size leak in 30 minutes or so.


A leak that fast will be able to be heard with your ears if the system is pressurized to around 100 psi.

------------------------------------------------------------------------

If there wasn't an oil spot around the outdoor unit then pressurize the system, pop the cover to the evaporator, and have a listen.

It's in 1 of 3 places. Indoor coil, outdoor coil, or lineset. Unless this is a package unit in which case the tech was just very lazy. Sometimes lineset leaks are hard to find if you can't get to the whole length of it.
I was told that he pressurized the system to 200+ lbs.but I was unable to see the gauges so I have to take his word for it and according to him it held pressure.
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Old 07-09-2015, 03:18 AM
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Originally Posted by 20biminitwist View Post
funny stuff here
Do any of you posting actually have a license to purchase refrigerant.

The OP states he can buy online and have it delivered?

Can you guys where ever actually purchase refrigerant without owning a recovery machine or a certificate from the EPA.

if no recovery machine how do you change a compressor or break into a charged system without venting?

back to the OP. If the unit is of age and has a leaking coil, get rid of it. The drop in gas for R-22 is not worth the hassle for an alternative.
I at least want to know where the leak is before I throw away an entire system. I don't know anything about central AC so I called in someone I thought was a pro. Theoretically a good system regardless of refrigerant type should never need a recharge. So if a system is using R-22 or anything else is kind of a moot point or am I missing something. I really do not have the time to research this stuff all I want is AC. As long as the AC doesn't work the house has become unusable to me once again.
And I do appreciate your help

Last edited by Mine Now; 07-09-2015 at 03:33 AM.
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Old 07-09-2015, 03:35 AM
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Originally Posted by baypro21 View Post
That's an extremely fast leak and a tech with a 1/4 brain should be able to find that size leak in 30 minutes or so.


A leak that fast will be able to be heard with your ears if the system is pressurized to around 100 psi.

------------------------------------------------------------------------

If there wasn't an oil spot around the outdoor unit then pressurize the system, pop the cover to the evaporator, and have a listen.

It's in 1 of 3 places. Indoor coil, outdoor coil, or lineset. Unless this is a package unit in which case the tech was just very lazy. Sometimes lineset leaks are hard to find if you can't get to the whole length of it.
Originally Posted by 20biminitwist View Post
funny stuff here
Do any of you posting actually have a license to purchase refrigerant.
Yes, do you?

The OP states he can buy online and have it delivered?
I don't like that

Can you guys where ever actually purchase refrigerant without owning a recovery machine or a certificate from the EPA.
I own 2

if no recovery machine how do you change a compressor or break into a charged system without venting?
I don't, that's against federal law

back to the OP. If the unit is of age and has a leaking coil, get rid of it.
Are you with one of those companies whose favorite diagnosis is "you need a new unit" ? Your eyes glaze over when you get to the house, walk around the corner, and see a system that's over 6 yrs old ? That's dispicable. I've got lots of customers going 2 to maybe 8 or more troublefree yrs on systems condemned by other companies.
The drop in gas for R-22 is not worth the hassle for an alternative.
Any flunky can lie, convince, and install new unnecessary systems, sometimes it takes just a little skill to diagnose the actual problem.
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Old 07-09-2015, 03:59 AM
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Originally Posted by baypro21 View Post
Any flunky can lie, convince, and install new unnecessary systems, sometimes it takes just a little skill to diagnose the actual problem.
Yes to this, and with building good and peoples schedule full there is more and more of this, and some companies that were thought to be reputable do it to.
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