I have some extra Schrader/service port caps that I drilled a tiny hole in. I screw that on and wipe some bubble juice over the hole. Even the smallest leak in the valve will blow a bubble.
Could be a vibrational leak or a heat dependent leak . Sometimes those leaks will not show up on a standing pressure leak but will expand when the pipes are heated or vibrating and seal up when the unit is off and resting and it will drive you nuts . I had a few units to do that to me . Great quality content . I watch your videos all the time .
I was thinking the same thing, but would expect even those types of leaks to yield to a sustained deep vacuum (although 600 microns isn’t deep enough, especially on a package unit).
That's why I used to check condensate for a positive hit. Refrigerant is heavier than air and will dissolve into the condensate. This is similar to checking a water cooled condenser for a leak. That would be including an electronic on the usual suspects. Schrader valves and isolatiin plus flare and piston fittings. Being only two years old and if the evaporator is aluminum odds on favorite is loosened or defective stems in the or a schrader valve(s). I also replace all factory plastic caps with new brass as there is also less likelihood of leaking intermittently with like and not dissimilar materials. I think I said enough for understanding. Since the vacuum test proved negative most likely again it was the valves.
You can also wrap the condenser with a tarp to isolate it and use a leak detector to help narrow it down just like the drain line method on the evaporator
@@adb99999999999 sometimes. unfortunately there are a lot of different types of leaks that can happen, though most of them are rare. I've gotten in the habit of doing a step test. start at 50 psi for 5-10 minutes, then 100, 200, 300, 400, 500. In residential you don't have that much time though so it's really situational most times.
I recently had a similar situation. Unit held 300 psi for 2 weeks. Evacuated to 400 no problem. Charged it up and instantly heard hissing. Pinhole in discharge line. Heat dependent leaks do occur
I tell all of our production workers and apprentices at it doesn’t matter how many years experience you have in this trade something will go right over your head. We are human and failures do happen. There are some days when we are off and not in the zone it happens we just try to learn by our mistakes. Every day is a learning experience. Anytime I replace Refrigerant, compressor, filter dryer, TXV or major components and dealing with the refrigeration circuit I always replace all the Schraders and Caps. I’m not 100% sure but I think POE oil is to blame for part of the Refrigerant leaks in the Schraders.
Maybe the unit was undercharged from factory. Or the leak is indeed from your Schraeder because you were doing the pressure test with the hoses attached. If you pull the hoses off and soap them I’d be curious if there is a leak. Back to being undercharged from factory I assume nothing anymore with QC
If the unit was undercharged from factory they would have called him back the next day of install since it's been working fine for the 2 years since. Schrader valves must be
I put in a ameristar heat pump a couple months ago. It was a split system. Started up and realized pressures/ superheat,subcooling where way off. It had passed nitro test and pulled great vacuum. Decided to pull out the little 410 that was in it which was not much more than what I added for Line set length. Never could find a leak. Still doing good so far. I know it's rare(in my experience) but I'm convinced it was low from the factory.
I had one Rheem condenser it was low 2 lbs I topped it off under warranty and performed a leak search. Week later bone flat. I pressure tested and pulled vacuum to 400 microns after 10 minutes it was 560ish I'll called it good. Recharged. Literally the next day was bone dry again. After further checks there was a tiny fracture on the low pressure switch and I checked both pressure switches and all braze joints with bubbles when I had a pressure test going
If service ports have caps on them with gaskets and they’re snug they’re not leaking. If they are the the hex style caps and a 1/4 turn snug with a valve core installed, that’s not your leak. If a system runs for a year and then some and you find it low on charge, it has a leak, subject to indoor and outdoor load. A couple passes with a leak detector to find nothing is cheaper then recovering, watching a pressure test, evacuating then recharging. Just leak search. This is sales pitch for a scale.
I’ve installed units that had NO refrigerant from the factory. Quality control is a thing of the past. If it ain’t the Schrader valves. It’s probably just factory mistake.
It would be interesting to use a infrared camera while the unit is running. It should show a cool spot wherever the leak is. Bad thing is if it it is in the indoor coil there may not be much luck in using the IR camera.
I agree about the Schrader valves. Pull the cores and replace. Come back in a day or two and use your leak detector without gauging up to see if you get any hits.
I’d take all covers off & move things around, sometimes rub outs & they leak more with constant movement from either compressor, fan motor or blower. Happed to me a couple of times on a WIF scenario though, one of the distributors had rubbed out & only way of finding it was moving them around
@@exclusive_148 If it loses nearly 50% of the charge in a year that is significantly bad leak. This lost nearly 50% of its charge in a few months. That is a horrible leak rate. He should have been checking everywhere for that leak to make sure its not leaking again. This being a heat pump as well a low charge will reduce their ability to heat their home not just affordably also effectively as loss of refrigerant means loss of capacity. The acceptable leak rate is around 30% in a year however as a commercial/industrial tech ANY LEAK is unacceptable and should be corrected because it ends up costing the customer money each year. What Erick is saying I have experienced something similar holding pressure until you move it. IE the hail guard on a condenser rubbing a hole in the coil. @Quality HVACR keep doing you dude, im sure theres more you did that you didn't put in the video. Not saying anything negative about you at all!
@@thejnelson88 It only lost 50% because the charge is a small amount. If A system had only 1 pound and it lost 8 ounces then that would be considered 50% and a "big" leak but it will still leak out at the same rate than a unit with 10 pounds but you wouldn't notice it on the 10 pound unit because the charge is large but in reality the leak rate is the same for both systems! Secondly speaking it was proved that the system doesn't have a leak because it passed the decay test. If it had a significant leak IT WOULDN'T HOLD 600 microns in 15mins! Thirdly - maybe it came undercharged from manufacturer plus the schrader came loose or something like that; *But theres no need to waste time pulling the whole thing apart if the system held vacuum or else your basically saying that micron readings are unreliable. 1 millionth of a meter is a pretty tiny measurement and should reflect a BIG LEAK like your saying. The other possibility might be that the leak is soooooo tiny that not even microns pick it up unless you leave it there for hours. If thats the case then thats the worst possible scenario.
I test the Schrader valves by holding the manifold attached for a period as pressure less Also after charging to test the valves. The new manifold catch small leaks easy if it builds up pressure by a leaking valve Just depressurize the hoses after charging and keep them on. A bad valve shows up. Our cascades has a charge less than 4 oz of R170 so a leak small as 1/4 oz kills the duty. Often seen the Schrader caps leaks so the way we do it is to use an anaerobe thread seal. That save us a lot of trouble. Never a repair without thread seal on caps here. Nice set up you use. Does that manifold show negative pressure as inches or PSI ? The one we have goes to -14,8 PSI instead so would be better if inches.
Standing pressure tests work great when you've got a decent leak. I can't tell you how many times I've had a system that was 70% low and after a 24-hour standing test, hadn't lost any pressure. In one example, I was convinced that someone was letting the refrigerant out at the property. However, after injecting a dye and returning a couple months later, I found a single drop of dye in the bottom of the condensation drain pan, confirming that the evaporator coil was actually leaking slowly. On a final note: Ameristar = Media junk, but it's still better than trane.
That's why I used to check condensate for a positive hit. Refrigerant is heavier than air and will dissolve into the condensate. This is similar to checking a water cooled condenser for a leak. That would be including an electronic on the usual suspects. Schrader valves and isolatiin plus flare and piston fittings. Being only two years old and if the evaporator is aluminum odds on favorite is loosened or defective stems in the or a schrader valve(s). I also replace all factory plastic caps with new brass as there is also less likelihood of leaking intermittently with like and not dissimilar materials. I think I said enough for understanding. Since the vacuum test proved negative most likely again it was the valves.
Good video. I normally allow an hour or more under a vacuum for leak checks first. If it holds, I pressure test it for only 10 to 15 minutes. I still don’t have Fieldpiece, but do like that scale.
I would strip the unit take a view for oil spots in known connection areas if not then I would leak test with bubble leak detector on particular copper connection points& shrader valves & also I would of repaired one of these the other day you can check behind the shrader core you will see a few brazed connections that’s where I found my leak , using bubble leak detector .
There are so many different types of leaks unfortunately. My guess is you’re right about the core, it was just EXTREMELY low when you topped it off and was running fine being low on refrigerant due to the cooler temps this time of year.
On a condenser tarp and sniffer it is too cumbersome unless you have no other calls. Self contained as a matter of efficiency dye is usually best if a you can't identify either the usual suspects or component dye is most cost effective. But if you want to really waste time you can cut out the condenser, pressurize and dunk in in water. That would be waste of time and energy. I have found them with ultra sonic, condensate, electronic, and dye but best practice is keep it simple from start and graduate.
I agree with Chris Davison. Sometimes a temperature or pressure dependent leak will only show up and leak during system operation. Very hard to find. I would settle on 350 psig for the nitrogen pressure test. I think 550 or 600 is too high. The valves and controls are not exactly the gold standard and return bends on the coils can become a leak with too much pressure. I feel if I can't find a leak at 350 I am not looking hard enough. I know system operating pressures are over 400 psig at times but still feel better at 350 for the test pressure. I also have brass Schreader valves with a gasket and add a small hole in the cap to use it only for leak checking the valve. That way you can spray big blue on the cap and not into the Schraeder itself. I like your video content and the way you present information. I have been in the business for over 40 years and you are one of the techs I follow.
The only thing I would have done differently is take the top off of the unit while it was pressurized and put bubble leak detector on the joints and see if anything pops up. You know you have a leak but it is a smaller one. I assume you use Big Blue and it is great for finding those sort of leaks.
Pro Tip: before you pressure test, flush the system with nitrogen for ~15 seconds. Then vacuum down to 1000 mincrons. Let it sit for ~3 minutes. Then pressure test. The reason is to get all the refrigerant out. The pressure will go up when as the refrigerant heats up. Also, the leak most likely is the schrader. I always change the cores when this happens and use metal caps.
I had one that leak and I put 500 psi nitrogen in it wouldn’t leak I finally got sick playing with it after couple trips I added dye to it found was the evaporator coil leaking guess it was vibrating and high pressure during heating season only when it was running
Could have been leaking as a vapor At the service port at Schrader valves I have seen it on a house before Where a new unit lost 2 pounds of refrigerant I checked indoor coil Outdoor coil outdoor service ports king valve No signs of leak Or oil Fine tuned system to 7ﾟ of sub cooling Created follow up call Came back Same thing again But this time lost one pound Changed Schrader valves Set a follow up Call For 3 weeks later came back to the house Checked split temp 22ﾟ on the outdoor temperature of 109 15ﾟ of super heat super heat 7ﾟ of sub cooling 😎 Merve 8 air filters Clean Indication that there was no more leak on system Another technician went there and performed yearly maintenance on the house Ask what the pressures were maintained maintaining 7ﾟ of sub cooling
It worked fine for a couple years. Suddenly it doesn't. A month or 2 after topping it off it's 2 lb low. Just use the leak detector. Those sorts of leaks are easy to find.
As for a tarp and sniffer especially with a self contained or RTU your better off with dye and then upon return use tenting. Tearing down is much more invasive. If it's a larger leak maybe ultrasonic. As for condensate with electronic and a positive hit then you have it isolated unless multiples. On a new unit and evaporator is leaking, replace. I like efficiency and more customers are satisfied with performance. Trying to tent and electronic is a good way to labor rate your customer into anger management....
Nicely done I would’ve done the same thing. Sounds like a leaky Schrader. The only thing I would’ve done differently is when doing a test tightness test I hook up my suction line temperature probe to the copper suction line. It factors in temperature of the copper pipes into leak test equation.
Exposed schraders, probably someone huffing refrigerant. Install cap locks. A heads up with wireless scales, including the FieldPeice, the signal can be blocked if a smart electrical meter is close by. I take care of a development where the scale would not connect due to the smart meters a few feet from the AC unit. If that is a heat pump, or the unit has a check type TXV, you'd need to attach to both sides for a proper evacuation.
Great Video Zac, you probably did have a schraeder leak. I have had issues with the same scale you used in this video, where it is not accurate at weighing in or recovering refrigerant. What got a different style scale and also got into a habit of weighing my tank before and after charging or recovering. Thanks again for great videos. 👍 👌
All these keyboard techs saying you should be able to pull below 500 microns or 300 microns within minutes hahaha… I don’t care what setup you are using; pulling down a compressor or accumulator with oil still present takes time. Period. Decay test holding under 1000 microns passes in my book all day long when evacuating an entire refrigeration circuit.
NOOOOOO….. at the end…. 14:30. Ocd but I purge my valve core tool so that air isn’t added to the lines. Try loosely inserting the Schrader valve, cracking the ball valve on the tool, then finish threading on the Schrader valve. Head scratcher… Warranty the system with manufacture, sell customer on labor of reinstall. Charge to cover hours. Gotta make your own work during slow season.
Why pressure test to 550? It's a waste of nitrogen. I shoot 50 and look for a leak first, then 150-200 for final leak check. Sometimes you can hear the leak before it hits 50. Saves nitrogen.
Pressurizing is a quick method but not the most thorough. Taking the extra time and using a leak detector is the best way to find it, because let’s face it, what was done is the same as topping it off again.
I’ve had one like that. The leak wouldn’t show itself with the fittings on if it was at the service valve. You take that valve off and spray you’ll get bubbles. Great video though.
Someone is been playing whit the freon valve , kids sometimes pulling out some freon if they have access, that's why i always install safety locks cap...
with the system under pressure you could have used an ultra sonic leak detector. i use the yellow jacket accuprobe ir. it uses an infrared sensor. you could pin point a leaking core under 10 minutes. this ameristar package by trane is factory assembled. the vulnerable spots for damage in shipping are the coils. your diagnostic approach is great, but i would have checked the cores first while under pressure.
1 time following up behind another tech. He pressure tested to 500psi, no drop, pulled a vacuum, and claims it held. He recharged and ran it.. it lasted a week before they called back.. I come behind him, pump the system up to 350psi and I can hear the hiss. It was on a U joint on the outdoor coil. It got worse if I shook the heat pump. So my assumption is it was a crack caused by vibration.
The only thing I would have done different was remove the valve core depressors from your smart probes and gave it 15 minutes to see if the valve cores were leaking. On rare occasions the service valves sealing surface to the valve core can be the problem.
I'd appreciate some advice if you or anyone else can spare a moment. My current employer wants to pay for me to get HVAC certified so that I can maintain and repair all of the HVAC equipment we have in the building. Heating, cooling, ice makers, walk-in cooler and freezer, stove, fryers, etc. Is it realistic to think I'd be up to the job after getting certified? Everyone on youtube makes it sound like you need a lot of experience too. I don't want to get into a situation where they've paid to get me certified but I'm still not able to do the job for lack of experience. They probably wouldn't like that much. So I'm a little nervous about it. Thanks.
It all depends on what you or your employer means by "certified"! Just know, in order to legally handle refrigerant or to work on refrigeration systems, you must be EPA608 Certified. However, Becoming certified does not replace formal air conditioning training. So my recommendation to you is for you to go to an accredited college that offers a degree or diploma program that has the EPA 608 embedded within the training. It is very important for you to learn how a refrigeration system is supposed to work. The best place to learn this is in school! There are so many techs out there who learn by OJT with someone who has the training or has been in the field for many many years. Some catch on very quickly but some never learn or are taught bad habits from the guy who really never got formal training! If you put 100% to learn the right way in school, you will not disappoint your employer. In addition, you will get all of the experience needed right there at your job! Sign up for training as soon as possible!
@@juliopinero3878 Thank you for that response. I feel a little better. It's a 31 credit program at an accredited college to get a "technical certificate." So I think I'll be good to go. Thanks.
6:26 - How does the position of the TEV and reversing valve affect the pressure testing or even purging with nitrogen if that's where you are in the process?
Great video, as usual. The only thing I would've done differently is I would've suggested to the customer, to have me inject a tube of Leak-Stop / UV Dye mixture (Nu-calgon) for a "seal or reveal" solution. Either, the leak-stop will seal it (if on the low side), or, the leak can be revealed via the UV light. Potentially, I may have also used my electronic leak detector. You use nearly the same equipment and come to nearly the exact conclusions, as I do. However, I am a terrible teacher, whereas you are a very good teacher. Thank you for taking the time to make these videos.
If the schraders were leaking you wouldn’t be able to tell from a pressure test because your hoses are on them. I would have pulled the hoses before dumping nitro and bubbled the schraders
Should have popped the top spray bubbles on both coils. Leak detector would have found that leak faster than all that. However if I did have to do what u did, it would have been completely apart to get at both coils, that's all. Nice scale btw , be safe out there 👍
Nice work Zac, Always enjoyed seeing your neat organized work. My suggestion would have been, since it was my installation, do a 24 hrs 400 lb (or what ever the manufacturer recommended pressure test is) , Pressure test at the start, since you know it's low already, from what gauges read. Also I would have recheck the condensor components for leaks with the leak detector while under the pressure test. not with soap (once you soap it, it gives you false readings on the detector). If it passed the 24hr test, your good. Also, a system like that should pull down below 500 mics easy and should get as low as 200 mics... something wrong there... But, we are all in the stands watching, easy to second guess someone else's work, You did a nice job and thank you for sharing!
If it has a micro channel evap coil I’ve had those not leak until system was running same with micro condenser coils, could be right at max psi but not leak and as soon as I turned it on it would be spraying out
My guess is it’s got a small leak somewhere. I own my own HVAC business and I have put in a lot of those units. The first mistake is that it’s an Amerisar. Those split system heat pump units had constant leaks in the evaporator coils. I know those units are cheaper than the Trane or American Standard, depending on the wholesaler you HVAC guy’s buy from. But they cause a lot of call backs.
Its leaking during operation as the evaporator and condenser change temp with the vibration of operating. You just haven't found the leak yet. I've been there a time or two myself.
Is it possible that you may have a stress crack somewhere along the lines ? Usually when the unit runs while it’s hot the cracks open up but once the unit stops running, they close. It’s like when you take a hot shower, your pours open up but then your done and your body cools, your pours close.
Only thing I'll mention is the pressure test, you really are supposed to only press up to the low side design pressure which is usually 250 for 410a. When they say low side,what they are referring to is the suction side of the compressor itself not the piping or evaporator. I realize it's a heatpump but in the end, the high and low sides of the compressor doesnt change. And the reason they don't want more than 250 is to do with the terminal plug, they say it can be damaged/cracked or worse,blow out, from excessive test pressures. They are made of a glass like material so makes sense as well. So unless youre working on a valved system where you can press up the low to 250 and the high to 550 or whatever, you should only use 250 for 410a. Just a heads up,great videos bro
That system would have been the perfect candidate for dye when you topped it off the first time. Then when you came back for your leak search, you could have ran your UV light around and looked for glowing
One additional note here is the mistake made here was not checking the usual suspects. The schrader can be easily checked with a sniffer with cupping your hand around the valve to prevent air currents from causing false positives. Also you can't rely only upon the chirp, indicator lights are also needed and no chemicals in the air. In this case that is doubtful but cleaning supplies etc can and usually do sniff positive.
Pretty sure you're supposed to weigh in 410a with the cylinder upside down? Its a blend that has the potential to fractionate due to the slightly different vapor pressures of each chemical.
My first theory would be, that if it's leaking when you're not there and not leaking when you are there, but it must be leaking from the places that you interact with. So I would expect the Schrader valves.
I agree with you I think the shredder valves were leaking some I do now is use my leak detector on the shredders or the good old spilt on the over the shredders found many leaks like your content
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I have some extra Schrader/service port caps that I drilled a tiny hole in. I screw that on and wipe some bubble juice over the hole. Even the smallest leak in the valve will blow a bubble.
This is brilliant.
Ac service tech.
Craig's method
I do the same thing now.
Could be a vibrational leak or a heat dependent leak . Sometimes those leaks will not show up on a standing pressure leak but will expand when the pipes are heated or vibrating and seal up when the unit is off and resting and it will drive you nuts . I had a few units to do that to me . Great quality content . I watch your videos all the time .
I was thinking the same thing, but would expect even those types of leaks to yield to a sustained deep vacuum (although 600 microns isn’t deep enough, especially on a package unit).
That's why I used to check condensate for a positive hit. Refrigerant is heavier than air and will dissolve into the condensate. This is similar to checking a water cooled condenser for a leak. That would be including an electronic on the usual suspects. Schrader valves and isolatiin plus flare and piston fittings. Being only two years old and if the evaporator is aluminum odds on favorite is loosened or defective stems in the or a schrader valve(s). I also replace all factory plastic caps with new brass as there is also less likelihood of leaking intermittently with like and not dissimilar materials. I think I said enough for understanding. Since the vacuum test proved negative most likely again it was the valves.
You can also wrap the condenser with a tarp to isolate it and use a leak detector to help narrow it down just like the drain line method on the evaporator
@@adb99999999999 sometimes. unfortunately there are a lot of different types of leaks that can happen, though most of them are rare. I've gotten in the habit of doing a step test. start at 50 psi for 5-10 minutes, then 100, 200, 300, 400, 500. In residential you don't have that much time though so it's really situational most times.
@@haydensi I like this method because it also saves Nitrogen. Blasting 550 psi into a line only to find you have not fixed your suspect joint sucks.
I recently had a similar situation. Unit held 300 psi for 2 weeks. Evacuated to 400 no problem. Charged it up and instantly heard hissing. Pinhole in discharge line. Heat dependent leaks do occur
Leaking Schrader core that got stuck open slightly and when you came you reset it when you put your hoses on it
I tell all of our production workers and apprentices at it doesn’t matter how many years experience you have in this trade something will go right over your head. We are human and failures do happen. There are some days when we are off and not in the zone it happens we just try to learn by our mistakes. Every day is a learning experience.
Anytime I replace Refrigerant, compressor, filter dryer, TXV or major components and dealing with the refrigeration circuit I always replace all the Schraders and Caps. I’m not 100% sure but I think POE oil is to blame for part of the Refrigerant leaks in the Schraders.
Maybe the unit was undercharged from factory. Or the leak is indeed from your Schraeder because you were doing the pressure test with the hoses attached. If you pull the hoses off and soap them I’d be curious if there is a leak. Back to being undercharged from factory I assume nothing anymore with QC
Low charge from the factory, cores leaking, or huffing, in that order
If the unit was undercharged from factory they would have called him back the next day of install since it's been working fine for the 2 years since. Schrader valves must be
Cores for sure. Even if it was undercharged from factory, it would have been two pounds low on the return trip unless there was a leak
I put in a ameristar heat pump a couple months ago. It was a split system. Started up and realized pressures/ superheat,subcooling where way off. It had passed nitro test and pulled great vacuum. Decided to pull out the little 410 that was in it which was not much more than what I added for Line set length. Never could find a leak. Still doing good so far. I know it's rare(in my experience) but I'm convinced it was low from the factory.
Add uv dye. Our favorite thing to do
Have had a set of old cps electronic scales ive had since my apprenticeship days. Over 10 years of service and still goes hard!
In the automotive field we actually have to use UV die to find leaks because they are so small a pressure test won’t tell you anything.
I had one Rheem condenser it was low 2 lbs I topped it off under warranty and performed a leak search. Week later bone flat. I pressure tested and pulled vacuum to 400 microns after 10 minutes it was 560ish I'll called it good. Recharged. Literally the next day was bone dry again. After further checks there was a tiny fracture on the low pressure switch and I checked both pressure switches and all braze joints with bubbles when I had a pressure test going
If service ports have caps on them with gaskets and they’re snug they’re not leaking. If they are the the hex style caps and a 1/4 turn snug with a valve core installed, that’s not your leak. If a system runs for a year and then some and you find it low on charge, it has a leak, subject to indoor and outdoor load. A couple passes with a leak detector to find nothing is cheaper then recovering, watching a pressure test, evacuating then recharging. Just leak search. This is sales pitch for a scale.
I’ve installed units that had NO refrigerant from the factory. Quality control is a thing of the past. If it ain’t the Schrader valves. It’s probably just factory mistake.
It would be interesting to use a infrared camera while the unit is running. It should show a cool spot wherever the leak is. Bad thing is if it it is in the indoor coil there may not be much luck in using the IR camera.
I agree about the Schrader valves. Pull the cores and replace. Come back in a day or two and use your leak detector without gauging up to see if you get any hits.
You can also try to add a uv dye just make sure it’s not one that has sealer.
I’d take all covers off & move things around, sometimes rub outs & they leak more with constant movement from either compressor, fan motor or blower. Happed to me a couple of times on a WIF scenario though, one of the distributors had rubbed out & only way of finding it was moving them around
i dont think he should take all the covers off to look for a rub out because the system isnt leaking significantly since it held the pressure test.
@@exclusive_148 It was 2 lbs low and they had just topped it off in the summer. That's a significant leak.
@@thejnelson88 But when they topped it off in the summer, how many months ago was that?
@@exclusive_148 If it loses nearly 50% of the charge in a year that is significantly bad leak. This lost nearly 50% of its charge in a few months. That is a horrible leak rate. He should have been checking everywhere for that leak to make sure its not leaking again. This being a heat pump as well a low charge will reduce their ability to heat their home not just affordably also effectively as loss of refrigerant means loss of capacity. The acceptable leak rate is around 30% in a year however as a commercial/industrial tech ANY LEAK is unacceptable and should be corrected because it ends up costing the customer money each year.
What Erick is saying I have experienced something similar holding pressure until you move it. IE the hail guard on a condenser rubbing a hole in the coil.
@Quality HVACR keep doing you dude, im sure theres more you did that you didn't put in the video. Not saying anything negative about you at all!
@@thejnelson88 It only lost 50% because the charge is a small amount. If A system had only 1 pound and it lost 8 ounces then that would be considered 50% and a "big" leak but it will still leak out at the same rate than a unit with 10 pounds but you wouldn't notice it on the 10 pound unit because the charge is large but in reality the leak rate is the same for both systems!
Secondly speaking it was proved that the system doesn't have a leak because it passed the decay test. If it had a significant leak IT WOULDN'T HOLD 600 microns in 15mins!
Thirdly - maybe it came undercharged from manufacturer plus the schrader came loose or something like that; *But theres no need to waste time pulling the whole thing apart if the system held vacuum or else your basically saying that micron readings are unreliable. 1 millionth of a meter is a pretty tiny measurement and should reflect a BIG LEAK like your saying.
The other possibility might be that the leak is soooooo tiny that not even microns pick it up unless you leave it there for hours. If thats the case then thats the worst possible scenario.
You could put some black light dye in if you have a tricky leak. Night time cold air is most likely when it leaks.
I test the Schrader valves by holding the manifold attached for a period as pressure less
Also after charging to test the valves. The new manifold catch small leaks easy if it builds up pressure by a leaking valve
Just depressurize the hoses after charging and keep them on. A bad valve shows up.
Our cascades has a charge less than 4 oz of R170 so a leak small as 1/4 oz kills the duty.
Often seen the Schrader caps leaks so the way we do it is to use an anaerobe thread seal.
That save us a lot of trouble. Never a repair without thread seal on caps here.
Nice set up you use. Does that manifold show negative pressure as inches or PSI ?
The one we have goes to -14,8 PSI instead so would be better if inches.
Standing pressure tests work great when you've got a decent leak. I can't tell you how many times I've had a system that was 70% low and after a 24-hour standing test, hadn't lost any pressure.
In one example, I was convinced that someone was letting the refrigerant out at the property. However, after injecting a dye and returning a couple months later, I found a single drop of dye in the bottom of the condensation drain pan, confirming that the evaporator coil was actually leaking slowly.
On a final note: Ameristar = Media junk, but it's still better than trane.
That's why I used to check condensate for a positive hit. Refrigerant is heavier than air and will dissolve into the condensate. This is similar to checking a water cooled condenser for a leak. That would be including an electronic on the usual suspects. Schrader valves and isolatiin plus flare and piston fittings. Being only two years old and if the evaporator is aluminum odds on favorite is loosened or defective stems in the or a schrader valve(s). I also replace all factory plastic caps with new brass as there is also less likelihood of leaking intermittently with like and not dissimilar materials. I think I said enough for understanding. Since the vacuum test proved negative most likely again it was the valves.
Good video. I normally allow an hour or more under a vacuum for leak checks first. If it holds, I pressure test it for only 10 to 15 minutes. I still don’t have Fieldpiece, but do like that scale.
I would strip the unit take a view for oil spots in known connection areas if not then I would leak test with bubble leak detector on particular copper connection points& shrader valves & also I would of repaired one of these the other day you can check behind the shrader core you will see a few brazed connections that’s where I found my leak , using bubble leak detector .
There are so many different types of leaks unfortunately.
My guess is you’re right about the core, it was just EXTREMELY low when you topped it off and was running fine being low on refrigerant due to the cooler temps this time of year.
Check in heat mode we have had some only leak in heat mode if it’s a heat pump .the leak was in the evaporator the aluminum had a small crack.
On a condenser tarp and sniffer it is too cumbersome unless you have no other calls.
Self contained as a matter of efficiency dye is usually best if a you can't identify either the usual suspects or component dye is most cost effective. But if you want to really waste time you can cut out the condenser, pressurize and dunk in in water. That would be waste of time and energy. I have found them with ultra sonic, condensate, electronic, and dye but best practice is keep it simple from start and graduate.
I agree with Chris Davison. Sometimes a temperature or pressure dependent leak will only show up and leak during system operation. Very hard to find. I would settle on 350 psig for the nitrogen pressure test. I think 550 or 600 is too high. The valves and controls are not exactly the gold standard and return bends on the coils can become a leak with too much pressure. I feel if I can't find a leak at 350 I am not looking hard enough. I know system operating pressures are over 400 psig at times but still feel better at 350 for the test pressure. I also have brass Schreader valves with a gasket and add a small hole in the cap to use it only for leak checking the valve. That way you can spray big blue on the cap and not into the Schraeder itself. I like your video content and the way you present information. I have been in the business for over 40 years and you are one of the techs I follow.
I think you were correct with shrader core leaking...but two pounds is a bit of loss..so leak check is appropriate
you mentioned a possible charge port leak, also sometimes a leak will open while operating due to temp change and vibration.
The only thing I would have done differently is take the top off of the unit while it was pressurized and put bubble leak detector on the joints and see if anything pops up. You know you have a leak but it is a smaller one. I assume you use Big Blue and it is great for finding those sort of leaks.
Pro Tip: before you pressure test, flush the system with nitrogen for ~15 seconds. Then vacuum down to 1000 mincrons. Let it sit for ~3 minutes. Then pressure test. The reason is to get all the refrigerant out. The pressure will go up when as the refrigerant heats up. Also, the leak most likely is the schrader. I always change the cores when this happens and use metal caps.
I had one that leak and I put 500 psi nitrogen in it wouldn’t leak I finally got sick playing with it after couple trips I added dye to it found was the evaporator coil leaking guess it was vibrating and high pressure during heating season only when it was running
Could have been leaking as a vapor At the service port at Schrader valves I have seen it on a house before Where a new unit lost 2 pounds of refrigerant I checked indoor coil Outdoor coil outdoor service ports king valve No signs of
leak Or oil Fine tuned system to 7ﾟ of sub cooling Created follow up call Came back Same thing again But this time lost one pound Changed Schrader valves Set a follow up Call For 3 weeks later came back to the house Checked split temp 22ﾟ on the outdoor temperature of 109 15ﾟ of super heat super heat 7ﾟ of sub cooling 😎
Merve 8 air filters Clean Indication that there was no more leak on system Another technician went there and performed yearly maintenance on the house Ask what the pressures were maintained maintaining 7ﾟ of sub cooling
Really like the content you’re putting out! Just getting into the industry and find myself watching your channel a lot! Keep it going!
Wait till I start my channel up in the mean time check out my Fpv drone footage 🤝
Thanks
It worked fine for a couple years. Suddenly it doesn't. A month or 2 after topping it off it's 2 lb low. Just use the leak detector. Those sorts of leaks are easy to find.
He is advertising for fieldpiece scale that why lol
As for a tarp and sniffer especially with a self contained or RTU your better off with dye and then upon return use tenting. Tearing down is much more invasive. If it's a larger leak maybe ultrasonic. As for condensate with electronic and a positive hit then you have it isolated unless multiples. On a new unit and evaporator is leaking, replace. I like efficiency and more customers are satisfied with performance. Trying to tent and electronic is a good way to labor rate your customer into anger management....
Nicely done I would’ve done the same thing. Sounds like a leaky Schrader. The only thing I would’ve done differently is when doing a test tightness test I hook up my suction line temperature probe to the copper suction line. It factors in temperature of the copper pipes into leak test equation.
Did you try pressure test with using only one port at a time to verify Schrader valves
That's a good way to test the valve core
Exposed schraders, probably someone huffing refrigerant. Install cap locks. A heads up with wireless scales, including the FieldPeice, the signal can be blocked if a smart electrical meter is close by. I take care of a development where the scale would not connect due to the smart meters a few feet from the AC unit.
If that is a heat pump, or the unit has a check type TXV, you'd need to attach to both sides for a proper evacuation.
Great Video Zac, you probably did have a schraeder leak. I have had issues with the same scale you used in this video, where it is not accurate at weighing in or recovering refrigerant. What got a different style scale and also got into a habit of weighing my tank before and after charging or recovering. Thanks again for great videos. 👍 👌
All these keyboard techs saying you should be able to pull below 500 microns or 300 microns within minutes hahaha… I don’t care what setup you are using; pulling down a compressor or accumulator with oil still present takes time. Period. Decay test holding under 1000 microns passes in my book all day long when evacuating an entire refrigeration circuit.
NOOOOOO….. at the end…. 14:30. Ocd but I purge my valve core tool so that air isn’t added to the lines.
Try loosely inserting the Schrader valve, cracking the ball valve on the tool, then finish threading on the Schrader valve.
Head scratcher… Warranty the system with manufacture, sell customer on labor of reinstall. Charge to cover hours. Gotta make your own work during slow season.
Why pressure test to 550? It's a waste of nitrogen. I shoot 50 and look for a leak first, then 150-200 for final leak check. Sometimes you can hear the leak before it hits 50. Saves nitrogen.
Pressurizing is a quick method but not the most thorough. Taking the extra time and using a leak detector is the best way to find it, because let’s face it, what was done is the same as topping it off again.
Dye is messy but is also undefeated
when checking for refrigerant leaks they could be temperature or pressure dependent or both.
I’ve had one like that. The leak wouldn’t show itself with the fittings on if it was at the service valve. You take that valve off and spray you’ll get bubbles. Great video though.
Don’t you have to hook up the suction clamp in tightness test for it to calculate copper temp into psi loss or gain?
nitrogen isn't truly inert that's why you see it swing at high pressures over time. Maybe schraders? since it's not leaking with the gauges on?
What a great method for finding a leak!
Did you adjust the sub cooling / superheat last time you check it.. keep them for records and job visiting for better accuracy!
Someone is been playing whit the freon valve , kids sometimes pulling out some freon if they have access, that's why i always install safety locks cap...
with the system under pressure you could have used an ultra sonic leak detector. i use the yellow jacket accuprobe ir. it uses an infrared sensor. you could pin point a leaking core under 10 minutes. this ameristar package by trane is factory assembled. the vulnerable spots for damage in shipping are the coils. your diagnostic approach is great, but i would have checked the cores first while under pressure.
1 time following up behind another tech. He pressure tested to 500psi, no drop, pulled a vacuum, and claims it held. He recharged and ran it.. it lasted a week before they called back.. I come behind him, pump the system up to 350psi and I can hear the hiss. It was on a U joint on the outdoor coil. It got worse if I shook the heat pump. So my assumption is it was a crack caused by vibration.
The only thing I would have done different was remove the valve core depressors from your smart probes and gave it 15 minutes to see if the valve cores were leaking. On rare occasions the service valves sealing surface to the valve core can be the problem.
I’ve seen Ted Cook of Anti DIY HVAC do that, but he used a stubby analog gauge( no hose) without the core depressor.
I'd appreciate some advice if you or anyone else can spare a moment. My current employer wants to pay for me to get HVAC certified so that I can maintain and repair all of the HVAC equipment we have in the building. Heating, cooling, ice makers, walk-in cooler and freezer, stove, fryers, etc. Is it realistic to think I'd be up to the job after getting certified? Everyone on youtube makes it sound like you need a lot of experience too. I don't want to get into a situation where they've paid to get me certified but I'm still not able to do the job for lack of experience. They probably wouldn't like that much. So I'm a little nervous about it. Thanks.
It all depends on what you or your employer means by "certified"! Just know, in order to legally handle refrigerant or to work on refrigeration systems, you must be EPA608 Certified. However, Becoming certified does not replace formal air conditioning training. So my recommendation to you is for you to go to an accredited college that offers a degree or diploma program that has the EPA 608 embedded within the training.
It is very important for you to learn how a refrigeration system is supposed to work. The best place to learn this is in school! There are so many techs out there who learn by OJT with someone who has the training or has been in the field for many many years. Some catch on very quickly but some never learn or are taught bad habits from the guy who really never got formal training!
If you put 100% to learn the right way in school, you will not disappoint your employer. In addition, you will get all of the experience needed right there at your job! Sign up for training as soon as possible!
@@juliopinero3878 Thank you for that response. I feel a little better. It's a 31 credit program at an accredited college to get a "technical certificate." So I think I'll be good to go. Thanks.
How many classes is the 31 credit TCC?
@@juliopinero3878 11
6:26 - How does the position of the TEV and reversing valve affect the pressure testing or even purging with nitrogen if that's where you are in the process?
Great video, as usual. The only thing I would've done differently is I would've suggested to the customer, to have me inject a tube of Leak-Stop / UV Dye mixture (Nu-calgon) for a "seal or reveal" solution. Either, the leak-stop will seal it (if on the low side), or, the leak can be revealed via the UV light.
Potentially, I may have also used my electronic leak detector.
You use nearly the same equipment and come to nearly the exact conclusions, as I do. However, I am a terrible teacher, whereas you are a very good teacher. Thank you for taking the time to make these videos.
If the schraders were leaking you wouldn’t be able to tell from a pressure test because your hoses are on them. I would have pulled the hoses before dumping nitro and bubbled the schraders
You have to leave it for a day or 2 if it’s that small of a leak
Can I use any vacuum pump oil on the fieldpiece pumps??
Have seen Schrader valves leak under run pressures and not leak under high pressure leak test
Should have popped the top spray bubbles on both coils. Leak detector would have found that leak faster than all that. However if I did have to do what u did, it would have been completely apart to get at both coils, that's all. Nice scale btw , be safe out there 👍
Is this the one unit, which you made a plenum for return air and supply duct running inside the plenum.
I have the same gauges you have. However am not able to sync the clamp to my 380. Can you?
Nice work Zac,
Always enjoyed seeing your neat organized work.
My suggestion would have been, since it was my installation, do a 24 hrs 400 lb
(or what ever the manufacturer recommended pressure test is) ,
Pressure test at the start, since you know it's low already, from what gauges read.
Also I would have recheck the condensor components for leaks with the leak detector while under the pressure test.
not with soap (once you soap it, it gives you false readings on the detector).
If it passed the 24hr test, your good.
Also, a system like that should pull down below 500 mics easy and should get as low as 200 mics... something wrong there...
But, we are all in the stands watching, easy to second guess someone else's work, You did a nice job and thank you for sharing!
Was the best level of microns u should reach on all ac units?
My experience with refrigerant is you never recover what you put in. Even if you recover it immediately. The oil holds some of it.
When in doubt run a stopleak i like that rectorseal treats up to 5 ton systems
If it has a micro channel evap coil I’ve had those not leak until system was running same with micro condenser coils, could be right at max psi but not leak and as soon as I turned it on it would be spraying out
you did a great job
but if it were me, I would use microbubble soap on the schrader valve
My guess is it’s got a small leak somewhere. I own my own HVAC business and I have put in a lot of those units. The first mistake is that it’s an Amerisar. Those split system heat pump units had constant leaks in the evaporator coils. I know those units are cheaper than the Trane or American Standard, depending on the wholesaler you HVAC guy’s buy from. But they cause a lot of call backs.
No traces of oil? Usually there would be some signs of oil somewhere
It could have something to do with the current temperature at the time. The atmospheric temp ?
Its leaking during operation as the evaporator and condenser change temp with the vibration of operating. You just haven't found the leak yet. I've been there a time or two myself.
I would have disconnected hoses while still under pressure test and Sprayed soap bubbles on the shredders
Is it possible that you may have a stress crack somewhere along the lines ? Usually when the unit runs while it’s hot the cracks open up but once the unit stops running, they close. It’s like when you take a hot shower, your pours open up but then your done and your body cools, your pours close.
Only thing I'll mention is the pressure test, you really are supposed to only press up to the low side design pressure which is usually 250 for 410a. When they say low side,what they are referring to is the suction side of the compressor itself not the piping or evaporator. I realize it's a heatpump but in the end, the high and low sides of the compressor doesnt change. And the reason they don't want more than 250 is to do with the terminal plug, they say it can be damaged/cracked or worse,blow out, from excessive test pressures. They are made of a glass like material so makes sense as well. So unless youre working on a valved system where you can press up the low to 250 and the high to 550 or whatever, you should only use 250 for 410a. Just a heads up,great videos bro
Maybe, the core valve was not sealed completely and wen you put the conectors hoses, is sealed back in place 🤔
I had a reversing valve body leak on me, same thing couldn’t find it and leak checked everything.
That system would have been the perfect candidate for dye when you topped it off the first time. Then when you came back for your leak search, you could have ran your UV light around and looked for glowing
One additional note here is the mistake made here was not checking the usual suspects. The schrader can be easily checked with a sniffer with cupping your hand around the valve to prevent air currents from causing false positives. Also you can't rely only upon the chirp, indicator lights are also needed and no chemicals in the air. In this case that is doubtful but cleaning supplies etc can and usually do sniff positive.
If your vacuum was running slow, couldnt that also be a sign of trapped refrigerant?
Pretty sure you're supposed to weigh in 410a with the cylinder upside down? Its a blend that has the potential to fractionate due to the slightly different vapor pressures of each chemical.
What type are your gauges?
My first theory would be, that if it's leaking when you're not there and not leaking when you are there, but it must be leaking from the places that you interact with. So I would expect the Schrader valves.
I still would of done a quick leak search and looks for some oil spots
I’m still learning so sorry if this sounds stupid. I thought you could only have a maximum of 500 microns looks like you were over 600 microns?
I’m starting my business and love all your videos amd tools you have . Thank you for all tips and making my next projects easyer
Field piece “sales guy”
I think you were right at the beginning, schrader core(s). 😎👊🏻
Why not recover all the refrigerant & leak test the system with nitrogen
Next time keep reversing valve energized during pressure test. Sometimes those suckers can mess with a test
The scale responds faster in the joblink app then the remote
Sometimes, that little quick leak check is not enough, 48 hours holding even 200 psi nitrogen will tell you even the smallest leak
What boots do you have?
I agree with you I think the shredder valves were leaking some I do now is use my leak detector on the shredders or the good old spilt on the over the shredders found many leaks like your content
I've had several run tru units undercharged this year not sure if they're still the same company though.
Not the same anymore, the new runtru/ameristar units are actually Trane units
If a system doesn't go below 500 microns more than likely there's a leak? Or I'm I wrong?
Great Demo
Think I saw Apple Watch ultra ? How is it?
Where can I purchase the 3/4 hose thanks
If in US you can get at tru tech tools or supply house when they decide to carry it.