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System Leaks

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dgunt

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Discussion starter · #1 ·
Hey Guys, I have a system that has a leak in it I think. The reason why is because today I got there and the pressure in the system were low. R 410A suction 40psig head 200psig. The first thing we did was pulled the gas out and weighed the charge and we were down half the charge. Then we started to pressure test to see if we could find anything. No luck. We left it at 450psig and going to let it sit for a day. I was just wondering what your guys thought was on using dye in a system to find a leak? I've always been told the only thing that should be in a refrigeration system is gas and oil. Thanks for your input.

Thanks
 
#3 ·
Pressure testing will determine if there is a leak but it won't tell you where, so start with leak an electronic leak detector add soap bubbles then go to more drastic measures if necassary.
 
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Discussion starter · #4 ·
We have soaped all the joints that we can get at. The only down fall is that the line set runs through a finished ceiling.

And I agree finding leaks is a tedious task. :eek2:

But like you said worse case do you guys think dye is ****ty or just lazy mans way out? haha
 
#5 ·
at least you know that you have to smash ceiling :eek:

installing refrigerant lines with joints through unapproachable area is one of the worst things i know where architects and dx systems sales reps work together against me by saying that it is not so big trouble and similar.
 
#7 ·
Without a good electronic leak detector it can be really hard to find a leak. If you're an HVAC tech I'd say "don't leave home without one". Soap bubbles are great to pinpoint a leak but unless you see something suspicious or get lucky you can drive yourself crazy using them. Depending on the size of the leak a good detector can pick up one in the indoor coil as soon as you walk in the door. I never had much luck with dye & rarely ever use it but some guys sear by it. I'm kind of impatient & don't like making another trip back either.
 
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Discussion starter · #8 ·
garyed said:
Without a good electronic leak detector it can be really hard to find a leak. If you're an HVAC tech I'd say "don't leave home without one". Soap bubbles are great to pinpoint a leak but unless you see something suspicious or get lucky you can drive yourself crazy using them. Depending on the size of the leak a good detector can pick up one in the indoor coil as soon as you walk in the door. I never had much luck with dye & rarely ever use it but some guys sear by it. I'm kind of impatient & don't like making another trip back either.
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I agree with you on the "don't leave home without a leak detector". Before we pulled the gas out we went around with our leak detector but didn't get any hits. ****ty thing about it was that it was raining out when we did this so that could've hurt things. So what i think i'm gonna do is leave it on pressure for a day. Then if its down cut the line set from the indoor and outdoor unit and just pressure the line set and the indoor and outdoor unit by themselves. Then hopefully I can get it pin pointed.

The unit that we are working on is York Affinity 18 SEER and its probably about 3 years old.
 
#9 ·
To start with, dye is oil so yes, you can use it. But an easier and more thorough way is to pull the charge, put a trace of R22 in it with N2 and then use an electric leak detector.
 
#10 ·
If it's leaked half its charge, you should have some decent oil spotting. It could be someone has just borrowed some refrigerant. I've heard of people using it for their meth lab production. Be on the lookout for skinny, scab covered individuals with rotten teeth
 
Discussion starter · #11 ·
bkmichael65 said:
If it's leaked half its charge, you should have some decent oil spotting. It could be someone has just borrowed some refrigerant. I've heard of people using it for their meth lab production. Be on the lookout for skinny, scab covered individuals with rotten teeth
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There has been a company there before me 3 different times and they keep blaming the leak on the service valve caps. (classic)
 
Discussion starter · #12 ·
Gunslinger said:
To start with, dye is oil so yes, you can use it. But an easier and more thorough way is to pull the charge, put a trace of R22 in it with N2 and then use an electric leak detector.
Click to expand...
I didn't know that the dye is a oil. Thanks for the info.

When I go back I will put a little trace of refrigerate in the system and go with the leak detector again.

Thanks
 
#13 ·
If it's very slow and hard to find, I pressurize both coils and then close both valves. When I come back I can tell if the evap has a leak. then I open valves and pressure will either drop or rise, (if it had dropped in the evap or lineset and the cond coils has no leak, then the pressure on the gages will rise when I open the gages - if i had no leak in the evap and open the gages and the pressure drops, then the leak in in the cond. I then know where to spend my efforts. of course this is assuming the valves are good and will seal off.
 
#14 ·
tonydykes55 said:
If it's very slow and hard to find, I pressurize both coils and then close both valves. When I come back I can tell if the evap has a leak. then I open valves and pressure will either drop or rise, (if it had dropped in the evap or lineset and the cond coils has no leak, then the pressure on the gages will rise when I open the gages - if i had no leak in the evap and open the gages and the pressure drops, then the leak in in the cond. I then know where to spend my efforts. of course this is assuming the valves are good and will seal off.
Click to expand...
correction, I meant "open the valves" not the gages
 
#15 ·
I would put a trace of r-22 in the system and bump up the pressure with nitro, if you can't find it that way I would start isolating the system and pressurize/leak check like that before I would use the dye. I'm not a big fan of the dye but that's just me. Good luck!
 
#16 ·
york was still having problems with their id coils, the ones that they were sending to replace the blue fins were having leaks show up so check that id coil real close
 
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#17 ·
All you need is just a twist of dye if you're using the injector. No reason to use a full tube through your gauges and dye up everything within a ten foot radius. if a new unit gets its annual maintenance then year three half the charge is gone?, I don't think opening the system and pressure testing everything is necessary if you trust your guys work and the service valves aren't damaged at install, add some dye in there if it lost that much then most times you can see it in minutes. We've replaced dozens of coils from brands listed above save yourself the sweat so you can move to good service calls. unless you've got yourself a healthy stockpile of fresh ready to fail 410a coils handy hit it with the the right dye set up then hit the road dont lose your shirt over it.
 
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