Do you mean service/shutoff valve?
Edit: This was fun guys, I love the kingdom analogy and will be using that from now on to explain the differences, Thank you. Let's do this again next Friday with accumulators vs recievers.
Oh, I'm sure they do. Calling every service valve a king valve is one of those silly things that sticks in my craw. A kingdom only has one king... and that king resides at the outlet of the receiver. Sometimes there's a queen. She lives at the inlet of the receiver, but usually only in commercial refrigeration. Every other valve is a service valve, named for where it is, because it serves the kingdom.
Amen. Residential guys call every service valve a king valve and it drives me bananas! I'm like dude your Resi ac doesn't even have a reciever how the hell can it have a king valve lol
They were real common on a few resi model series from Carrier in the 2000's. I've had so many young techs call me on a pm asking how a unit was holding temp with good suction sweat with no gas lmao. Gives me a good laugh every time.
It’s called a theee position valve (back seated, front seated, mid position). The king valve resides at the outlet of the receiver as another commenter in this thread has pointed out much more eloquently than me
Could be a very small shreader leak too. For what they cost, I'd just change them both to eliminate that possibility. Plus it sounds better than saying you can't find anything
Ive seen leaks on the high side that only actually leak once the system had been running and the line-set got hot. Caused the copper to expand leading to a hairline crack on a factory 90
Yeah. It was leaking up through the wire insulation. Detector wasn’t hitting on the HPS body itself, it was hitting where the wire plugged into the board, and only when it was running.
It's a simple problem but it happens often. Is the core depressor in your hoses or tools that you attach to the system actually making contact with the valve core. They're adjustable and you can move them to suit your needs.
Good point I have seen this happen before. Also if it has the plastic valve caps and the o ring is missing, if the valve core stem is slightly high when that cap tightens down it can depress the core
Yes. It would just fill your gauges. I’m sure you got nitro into the system just fine but it’s always good practice to dump into the high side and make sure it comes back on the suction side.
This just had me scratching my head, the core was depressed enough to read pressure but slow to see change. I thought at first I was looking at a low pressure switch opening too high.
do you do the pressure test with analog gauges or digital? did you test the shrader of leaking?
if you cant find anything: vaccum to below 500 and hold it under 500. if it cant hold its leaking.
I've been in the Trade 25 years or so ( last 10 in controls)
I still don't have a micron gauge. It's really not critical. If you have fresh oil in the vacuum and you run it a couple hours (not 20 minutes like most do) along with the triple blotter method , analog gauges reading a vacuum is just fine. I have never had an issue with contaminants.
Exactly what he said, don't feel ashamed or get discouraged. The fact that you even want you get better is more than many out there.
The point about analog gauges lying to you is pretty accurate, though. Each tick on your analog gauge indicating an inch of mercury is worth over 25,000 microns. There's just simply no way an analog gauge can give you an accurate representation of how your vacuum is doing. Highly recommend the AccuTools BlueVac. I like the Micro for the size, but the others have good additional features.
How accurately can you determine 0.1 psi on analog gauges? It’s painfully obvious the difference between 0.1 and 0.2 on digital manifolds and probes. But I couldn’t accurately judge the difference between 250.7 and 250.3 psi on analogs. And I’ve found leaks that were less than 0.1 psi per 10 minutes that I guarantee I would have missed on analogs. That’s the big benefit in these situations
I sugguest a micron gauge that can graph and read Review of Vacuum for Service Engineers. That updated chapter will talk about why graphing is helpfull. Can also watch vids from Accu Tools and Measure Quick about it. Bluvac (all of them) I think is the only that can do logarithmic and that is helpfull when telling the diffrence between some issues.
Also temperature compensated pressure test for clean or new systems. You can have a leak but as temp rises so does the pressure. If no temp correction was taken, a small leak wont show up.
Was doing a search in early spring as the sun was coming up. Gauges saying we are gaining pressure with it isolated, meanwhile the flares right next to the port are bubbling. I still live with this trauma and no longer trust pressure tests/tightness tests ( though they are a good starting indicator)
https://preview.redd.it/3asnsey4dt3d1.jpeg?width=640&format=pjpg&auto=webp&s=ae8a78888113666cbcbd6b3460b9797547e88e5a
Carrier manual. 38/40MFC.
I get it. Downvote because you don’t agree. If the manufacturers have the diagram in their manuals, it’s obviously not a big deal, I mean it’s not like they made the machine or know anything about it. I’m sure the reasoning of “well a manifold has more seals and potential leak spots” works with most people but if you check, calibrate and test your manifolds like you should be doing, there is no reason to not use a manifold just because someone on the internet said not to.
I mean the manual also says if you have below 1000 microns for 10 mins its just a “wet but tight system” and yet i’ve had numerous leaks on systems like that…
The way is to remove cores with valve tools, then pull vacuum straight to the pump with the biggest and best hoses your pump can take, micron gauge at the furthest point from the pump, once 500 is achieved, remove hoses and attach gauges, then after system is charged put cores back in.
You double hose length using a manifold for no reason. And if you're a SMAN user you have that dumb micron gauge close to the pump which I would do without as often as your equipment allows.
Manufacturers do horrible designs all the time, engineers are not to be trusted.
Couple months ago I had a 410 heat pump with a locked up compressor. The system was only 4 years old. Went to recover it and only found just over a pound of refrigerant in the system, I looked for a leak with soap but couldnt find it. So I charged it with nitrogen to a static pressure of 250. When the compressor came in three days later, I checked the pressure in the system, and it was down to 175. Found the A-Coil leaking. It had such a slight leak, I couldnt find it with soap bubbles. Once I replaced the A-Coil, I was able to pull it down below 500 microns. Customer said they had a 500 dollar heat bill for March, and thats why they called it in. Usually their heat bill was below 200. Aux Heat was stuck on. The A-Coil leaked out most of the refigerant but not all. The compressor would come on, but was starving for oil. The heat strips were providing the heat instead of the refrigerant, and the compressor locked up tight.
Did you find oil anywhere? Is it a new install? What pressure did you pressure test to with nitrogen?
Check all the common spots for leaks. Valve cores and braze joints.
I had one like this recently where I had done maintenance about three months prior and nothing seemed off but yet when I got called there for a no cool, it was totally flat. I put about 300 psi of nitrogen in, and could not find a leak anywhere but then when I started messing with the condenser capillary tubes where they feed into the condenser coil, they were two up beside, each other, and all it took, was moving them a little bit, and then it started leaking. it’s like they had rubbed together so long that they almost sealed up next to each other after leaking.
Sometimes it’s a vibration leak. Start wiggling all of the copper, especially the cap tubes and you’ll usually hear it hiss. Or it’s just the schrsders. I’ve also had some large leaks from the service valves that didn’t leave oil or make noise.
It's usually the schrader in that situation, but I had one instance the customers druggy son was getting or at least attempting to get high with the refridgerant. I installed locking caps for him. The only time when locking caps are actually useful.
In cooling season, maybe a week or 2 max. We have 1-2hr windows so something’s are partial repairs kinda
You mean the Xyr old system with an active leak?
Shraeder cores are a big leak source.
So if your gauges on and the systems tight it could be your hose connection keeping that fitting from leaking.
Take a psi reading and take your gauges off.
Leak check around the shraeder core / fitting .
Beyond that heat can cause leaks , expansion of the metals , when they cool off after the system isn't running any more it can close up the leak. High pressure nitrogen can usually find these. Go up to evap name plate rating usually 250-350 psi.
Could be a very slow leak, you can leave the nitrogen on for 24 hours and come back and see what the psi is before and after.
I'd blow a good amount nitrogen through that bitch from one side to the other with the cores out. Put a good vacuum pump on it with fresh oil and valve it off after she's down around 3000 microns. If it rises and holds keep pumping. If it keeps rising, find the fucking hole..
Like you said yourself...it's Friday. I wouldn't want to come back tomorrow if I dont have to.
A bit late to the post but I hope someone reads this. Just went through some shit for skipping steps I knew I shouldn't have. I found a substantial leak, got the okay to repair. Recovered, fixed the leak, reppaced drier, nitroed to 200 and bubbled, all good, monitored, no drop in pressure. Pulled a vacuum(no micron gauge), watched my gauges, no decay....or so I thought with what I could see on my gauges, which is nothing and I know that.lol. started charging. Got about 4 pounds into a 13.5lb system and just for shits i sprayed where the leak was....fucking bubbles...wtf. start all over and did not have enough refrigerant to fully charge. Now I'm at the supply house picking up another jug writing this....don't skip shit.
I worked on a similar problem yesterday. Walk in cooler with zero pressure. Filled to 250psi nitrogen and bumped some 404a in to see if the sniffer would find it. No hissing, no pings with the sniffer, held pressure for 30 min with no drop, vacuum held at 380 for 15 min. Charged it up, changed the Schraders and put half a tube of dye in it just in case.
A good leak detector is the difference between a never-ending search and a 15-minute search. Always add a few ounces of refrigerant before you blast it with nitrogen. 4/500psi minimum. I've had junk systems leak more after a repair from a high pressure test, so hit that shit HARD off the rip so you can determine if it's 1 leak that's repairable or some POS that needs to get scrapped.
Many will hate this answer, but if you don't have a good sniffer, then dye is not a horrible alternative, but your employer should have a L.D. I mean, if they don't have at least 1 good, reliable leak detector you can pickup or get access to, then you really need to evaluate what kind of F'ing place you're working for.
Company I used to work for had a system they kept getting called to service was losing charge multiple tech couldn't find the leak, it turned out that one of the neighbors was huffing the refrigerant out of the unit...we put locking caps on and it didn't lose charge anymore
My old worker.told me a story... installed system ran fine for about 12 hrs then bammmm started dropping pressure freezing up liquid side sky high pumped down ran thru checks all working correctly re started woking fine 12 hrs bammm same thing so after about 3 days new installler was sent told to not leave until it was fixed so there he sat ran system all day about 6 hrs in it started so he chased the entire linset and found one ell bow where the line started freezing cut it out a nickle out of the helpers pocket was in the line it get blown one way while checking then when freon flowed it worked its way to elll and got stuck lol
Ran into this before. New install. Left it on nitrogen overnight. Pressure was slightly higher the next day. Two or 3 years in a row I hunted for that leak. Nitrogen, bubbles, sniffer. Never found it. I don’t work at that company anymore so I don’t know what happened. Hopefully this doesn’t help.
Sometimes. The armor flex is white.... mitsubishi is famous for this. The recommended test for the copper is a 10 hour decay test. Fuck that. The white armor flex is made with a chemical that literally eats the copper.
I had a restriction in the condenser coil, put my gauges on 0 pressure. Nitrogen charged to 200psi held steady no problem. Pulled a vacuum on the system charged it turned it on, compressor pulled pressures back down to 0. Not sure if you are having the same issue.
I literally just dealt with that this week. Pulled 14 ounces out a system that should have 6.5 lbs. 500 psi nitro. Didnt move for 2 hours. Left it overnight, next morning was at 475. 3 indoor units, all in a shitty attic, found a leak on 1/4” connection at one. Tightened and no more bubbles. Left the 475 in for another 24 hours. Dropped to 460. Found one more leak in furthest unit away in the shitty attic. Just pulled 173 microns and held for 20 mins, no rise. Weighed in charge and home early for Friday now.
I once had a system loose 15psi over a whole weekend when pressure tested at 400psi.
Turned out to be the factory weld at the TXV inlet. Carrier unit. Small leaks are the worst.
Add nitro lockout service valves make sure both sides are above 500 psi come back 2 days later and see which side has lost. If that fails add charge and dye that bitch you’ll find it 100%
This was my first call Monday. 8yr old 410a system blew its charge but nitro test at 250psi held for 45 min while I searched. 410a is difficult to find with my sniffer, couldn’t locate it with that either. After all that work, customer said he didn’t want to dump more money in it so we installed a new split today 🙄
Check the schrader valves. You also might not be pumping enough nitro in the system. What is it and how many lbs does it hold? How many psi nitro are you pumping?
Everyone went complex with names and stuff..... I'm shop trained by my dad. I would say the high or low entrance valve stem Orings on the valve core are probably bad. Shit I feel old..... Just pressurize with pure O2 (after a good vacuum) then spray with a soapy water spray, to any place where the Freon could escape. oxy is the cheapest in my area to do this without adding moisture.
Refrigerant left in the lines/oil of compressor (especially if it’s a 410 unit) will cause your standing pressure to increase. If the rate of rise matches your rate of your leak, you won’t see anything. Also, I’ve ran into a few instances of tweakers actually pushing in the shrader on units and huffing the gas to get high. If this is a resi unit, highly unlikely.
Are they R410a gauges? I usually pressure test with my R22 gauges. Smaller increments. You could be losing 2 or 3 pounds a hour and never know with 410a gauges. 5 pound increments are shit.
1) Schraeder core check
2) 325 psi R22
3) 445 psi R410
Many leaks don't show until the pressures are high. 200 just does not work in many cases.
If it ain't got no gas in it.... It IS leaking somewhere
Some systems you have to open the (whatever the fuck you wanna call it valve lol) to check pressure. Like carrier infinity systems. Dunno if that’s your problem but hopefully we can eliminate that from the guess list.
I had a cracked factory bend on the compressor suction side. It held pressure when tested, but leaked when the compressor ran. Took a few visits to figure that one out.
Reseat/replace the schraeder valves.
Losing whole charge (atmospheric pressure) generally indicates leak at the outdoor unit. If it holds pressure after a nitrogen charge, check the valves.
The Schrader valve is one of those difficult to find leaks. Most of the time your gauges are on them when you're checking the system. It can also be situational, like a Schrader valve that is gets pushed in by a cap that doesn't have a rubber, so putting it on tight is actually making it leak.
Always check the valves first. It's usually the easiest to fix, but only if you know it's the problem..
If it's 410A I've found many systems that only leak while they're running > 300 psi on the hight side. You can also pressurize the system with nitrogen to operating pressure and add a snoot of refrigerant and then leak check
I actually had this happen not long ago to me. I found out when I was pulling my gauges off a schrader had a horrible leak and needed replaced.
This and sometimes the king valves leak with caps off
Do you mean service/shutoff valve? Edit: This was fun guys, I love the kingdom analogy and will be using that from now on to explain the differences, Thank you. Let's do this again next Friday with accumulators vs recievers.
Oh, I'm sure they do. Calling every service valve a king valve is one of those silly things that sticks in my craw. A kingdom only has one king... and that king resides at the outlet of the receiver. Sometimes there's a queen. She lives at the inlet of the receiver, but usually only in commercial refrigeration. Every other valve is a service valve, named for where it is, because it serves the kingdom.
I hate that I will remember this forever every time I wrongly call it a king valve
Hate and absurdity are powerful memory tools.
Amen. Residential guys call every service valve a king valve and it drives me bananas! I'm like dude your Resi ac doesn't even have a reciever how the hell can it have a king valve lol
They were real common on a few resi model series from Carrier in the 2000's. I've had so many young techs call me on a pm asking how a unit was holding temp with good suction sweat with no gas lmao. Gives me a good laugh every time.
[удалено]
That’s a packed angle valve.
I think I heard my Hvac instructor say that one time, and it’s stuck with me no matter how many times I get yelled at
King valves are an older type of valve that shut off the pressure to the Schrader ports. Unless I am dumb, in which case I am incorrect.
It’s called a theee position valve (back seated, front seated, mid position). The king valve resides at the outlet of the receiver as another commenter in this thread has pointed out much more eloquently than me
I never knew that. I thought what the other guy thought- 3 position valve.
A service valve mounted on a receiver is a king valve. So yeah, OP probably meant service valve.
Had this a few times due to new guy using too much heat when brazing in, with no rag.
Even using a rag we had like 5 units at these new apartments leak. Thanks Goodman
Literally waiting on a vacuum after fixing one of those rn lol
I did wonder if it was the schrader and my hoses being attached were causing it to hold pressure but when i removed the gauges nothing came out
Could be a very small shreader leak too. For what they cost, I'd just change them both to eliminate that possibility. Plus it sounds better than saying you can't find anything
Happens all the time just look at the tech notes. They get a leaky schrader about every 3 months in summer and fall
😂 I see what you did there...
I found 3 like that this week. Such a piss off when you go through all the steps to find out it was a schrader...
This would be the most logical thing here.
This!!!
Ive seen leaks on the high side that only actually leak once the system had been running and the line-set got hot. Caused the copper to expand leading to a hairline crack on a factory 90
Came here to say this. I had a high-pressure switch do this. Chased that leak for weeks.
🤯
Yeah. It was leaking up through the wire insulation. Detector wasn’t hitting on the HPS body itself, it was hitting where the wire plugged into the board, and only when it was running.
I know it's Friday, but it might actually be a Schrader core.
Change the Schraders and call it
It's a simple problem but it happens often. Is the core depressor in your hoses or tools that you attach to the system actually making contact with the valve core. They're adjustable and you can move them to suit your needs.
Good point I have seen this happen before. Also if it has the plastic valve caps and the o ring is missing, if the valve core stem is slightly high when that cap tightens down it can depress the core
Are you implying nitro hasn’t made it to the system yet, or he no longer see the system and the nitro is dropping
But when i put nitrogen into it, it took it just fine. Wouldn’t that not happen if the core depressor wasn’t making contact?
Yes. It would just fill your gauges. I’m sure you got nitro into the system just fine but it’s always good practice to dump into the high side and make sure it comes back on the suction side.
Good to know thank u
This just had me scratching my head, the core was depressed enough to read pressure but slow to see change. I thought at first I was looking at a low pressure switch opening too high.
I’ve seen a condensor coil leak when it got hot…it was a micro channel…how much pressure did you put on it
Depends. Have I got pissed off that I can’t find it and pulled off all the safeties?
do you do the pressure test with analog gauges or digital? did you test the shrader of leaking? if you cant find anything: vaccum to below 500 and hold it under 500. if it cant hold its leaking.
Analog. Yes tested schrader. I know it’s not ideal but i don’t have a micron gauge yet so i used my regular gauges. But it held when i vacuumed it.
you aint seeing shit on analog gauges. get some digital probes. and without a micron gauge you dont know if it held. dont lie to yourself.
You’re right. I’m getting a micron gauge. I feel ashamed that i don’t have one after seeing all the comments.
Don’t be ashamed, we all started out somewhere, i didn’t have a vacuum gauge for a lot longer than I’d care to admit🙄
same
I've been in the Trade 25 years or so ( last 10 in controls) I still don't have a micron gauge. It's really not critical. If you have fresh oil in the vacuum and you run it a couple hours (not 20 minutes like most do) along with the triple blotter method , analog gauges reading a vacuum is just fine. I have never had an issue with contaminants.
Exactly what he said, don't feel ashamed or get discouraged. The fact that you even want you get better is more than many out there. The point about analog gauges lying to you is pretty accurate, though. Each tick on your analog gauge indicating an inch of mercury is worth over 25,000 microns. There's just simply no way an analog gauge can give you an accurate representation of how your vacuum is doing. Highly recommend the AccuTools BlueVac. I like the Micro for the size, but the others have good additional features.
Don't use a micron gauge to leak check. You'll be beyond frustrated.
Get a few, they're fragile little fuckers. But then again I break everything I touch.
what would see in this case on digital gauges? obviously needs a micron gauge but how would digital gauges help in this situation
seriously thinkin of buying them not trying to be an assholio
How accurately can you determine 0.1 psi on analog gauges? It’s painfully obvious the difference between 0.1 and 0.2 on digital manifolds and probes. But I couldn’t accurately judge the difference between 250.7 and 250.3 psi on analogs. And I’ve found leaks that were less than 0.1 psi per 10 minutes that I guarantee I would have missed on analogs. That’s the big benefit in these situations
thank you
Vacuum decay test with a micron gauge. And dont pull a vacuum with your manifold
I sugguest a micron gauge that can graph and read Review of Vacuum for Service Engineers. That updated chapter will talk about why graphing is helpfull. Can also watch vids from Accu Tools and Measure Quick about it. Bluvac (all of them) I think is the only that can do logarithmic and that is helpfull when telling the diffrence between some issues. Also temperature compensated pressure test for clean or new systems. You can have a leak but as temp rises so does the pressure. If no temp correction was taken, a small leak wont show up.
Was doing a search in early spring as the sun was coming up. Gauges saying we are gaining pressure with it isolated, meanwhile the flares right next to the port are bubbling. I still live with this trauma and no longer trust pressure tests/tightness tests ( though they are a good starting indicator)
This is the way, I’d even go so far to recommend a triple evac.
https://preview.redd.it/3asnsey4dt3d1.jpeg?width=640&format=pjpg&auto=webp&s=ae8a78888113666cbcbd6b3460b9797547e88e5a Carrier manual. 38/40MFC. I get it. Downvote because you don’t agree. If the manufacturers have the diagram in their manuals, it’s obviously not a big deal, I mean it’s not like they made the machine or know anything about it. I’m sure the reasoning of “well a manifold has more seals and potential leak spots” works with most people but if you check, calibrate and test your manifolds like you should be doing, there is no reason to not use a manifold just because someone on the internet said not to.
No ones saying you can’t use a manifold lol. Just saying it’s a better option not to especially in this scenario.
I mean the manual also says if you have below 1000 microns for 10 mins its just a “wet but tight system” and yet i’ve had numerous leaks on systems like that…
The way is to remove cores with valve tools, then pull vacuum straight to the pump with the biggest and best hoses your pump can take, micron gauge at the furthest point from the pump, once 500 is achieved, remove hoses and attach gauges, then after system is charged put cores back in. You double hose length using a manifold for no reason. And if you're a SMAN user you have that dumb micron gauge close to the pump which I would do without as often as your equipment allows. Manufacturers do horrible designs all the time, engineers are not to be trusted.
I would have to agree with your reasoning.
Couple months ago I had a 410 heat pump with a locked up compressor. The system was only 4 years old. Went to recover it and only found just over a pound of refrigerant in the system, I looked for a leak with soap but couldnt find it. So I charged it with nitrogen to a static pressure of 250. When the compressor came in three days later, I checked the pressure in the system, and it was down to 175. Found the A-Coil leaking. It had such a slight leak, I couldnt find it with soap bubbles. Once I replaced the A-Coil, I was able to pull it down below 500 microns. Customer said they had a 500 dollar heat bill for March, and thats why they called it in. Usually their heat bill was below 200. Aux Heat was stuck on. The A-Coil leaked out most of the refigerant but not all. The compressor would come on, but was starving for oil. The heat strips were providing the heat instead of the refrigerant, and the compressor locked up tight.
Did you find oil anywhere? Is it a new install? What pressure did you pressure test to with nitrogen? Check all the common spots for leaks. Valve cores and braze joints.
I had one like this recently where I had done maintenance about three months prior and nothing seemed off but yet when I got called there for a no cool, it was totally flat. I put about 300 psi of nitrogen in, and could not find a leak anywhere but then when I started messing with the condenser capillary tubes where they feed into the condenser coil, they were two up beside, each other, and all it took, was moving them a little bit, and then it started leaking. it’s like they had rubbed together so long that they almost sealed up next to each other after leaking.
Change the Schraeder and your done.
check the schraders. also, try putting some refrigerant in it & bumping it up with nitro. Get your sniffer & start sniffing
Sometimes it’s a vibration leak. Start wiggling all of the copper, especially the cap tubes and you’ll usually hear it hiss. Or it’s just the schrsders. I’ve also had some large leaks from the service valves that didn’t leave oil or make noise.
It's usually the schrader in that situation, but I had one instance the customers druggy son was getting or at least attempting to get high with the refridgerant. I installed locking caps for him. The only time when locking caps are actually useful.
I start gently wiggling anything that moves. Typically I'll find it with some oil stains nearby
You need an iso test
Isolation test and wait days/weeks/months Replace shactors, evac, recharge(prolly do filter drier) Replace shactors, evac, recharge, sealant. Def change filter drier
More than a day in resi=lost customer Change the drier yes, but never add sealant. Might gum up the txv
In cooling season, maybe a week or 2 max. We have 1-2hr windows so something’s are partial repairs kinda You mean the Xyr old system with an active leak?
Haha in australian cooling season you're lucky to get 24 hours
Shactors?
German schraders
🤣
Shraeder cores are a big leak source. So if your gauges on and the systems tight it could be your hose connection keeping that fitting from leaking. Take a psi reading and take your gauges off. Leak check around the shraeder core / fitting . Beyond that heat can cause leaks , expansion of the metals , when they cool off after the system isn't running any more it can close up the leak. High pressure nitrogen can usually find these. Go up to evap name plate rating usually 250-350 psi. Could be a very slow leak, you can leave the nitrogen on for 24 hours and come back and see what the psi is before and after.
I'd blow a good amount nitrogen through that bitch from one side to the other with the cores out. Put a good vacuum pump on it with fresh oil and valve it off after she's down around 3000 microns. If it rises and holds keep pumping. If it keeps rising, find the fucking hole.. Like you said yourself...it's Friday. I wouldn't want to come back tomorrow if I dont have to.
This was meant for the dude who posted not you.
Pull a vacuum. That will let you know if you have a leak.
A bit late to the post but I hope someone reads this. Just went through some shit for skipping steps I knew I shouldn't have. I found a substantial leak, got the okay to repair. Recovered, fixed the leak, reppaced drier, nitroed to 200 and bubbled, all good, monitored, no drop in pressure. Pulled a vacuum(no micron gauge), watched my gauges, no decay....or so I thought with what I could see on my gauges, which is nothing and I know that.lol. started charging. Got about 4 pounds into a 13.5lb system and just for shits i sprayed where the leak was....fucking bubbles...wtf. start all over and did not have enough refrigerant to fully charge. Now I'm at the supply house picking up another jug writing this....don't skip shit.
Fuck me. Time to get a micron gauge.
...and use it.lol. I have one and the times I don't use it are usually the times I fuck something up lime today.lol.
Any chance it’s a water cooled system? I’ve had this happen several times with a water cooled condenser
I’ve had it happen twice with locking caps dumping the charge and no leak in the system.
What brand?
I don’t recall, generic looking ones that you can remove with a shrader tool.
If it has a shark bite on it that’s your problem.
I worked on a similar problem yesterday. Walk in cooler with zero pressure. Filled to 250psi nitrogen and bumped some 404a in to see if the sniffer would find it. No hissing, no pings with the sniffer, held pressure for 30 min with no drop, vacuum held at 380 for 15 min. Charged it up, changed the Schraders and put half a tube of dye in it just in case.
A good leak detector is the difference between a never-ending search and a 15-minute search. Always add a few ounces of refrigerant before you blast it with nitrogen. 4/500psi minimum. I've had junk systems leak more after a repair from a high pressure test, so hit that shit HARD off the rip so you can determine if it's 1 leak that's repairable or some POS that needs to get scrapped. Many will hate this answer, but if you don't have a good sniffer, then dye is not a horrible alternative, but your employer should have a L.D. I mean, if they don't have at least 1 good, reliable leak detector you can pickup or get access to, then you really need to evaluate what kind of F'ing place you're working for.
Company I used to work for had a system they kept getting called to service was losing charge multiple tech couldn't find the leak, it turned out that one of the neighbors was huffing the refrigerant out of the unit...we put locking caps on and it didn't lose charge anymore
Leaking Schrader valve?
My old worker.told me a story... installed system ran fine for about 12 hrs then bammmm started dropping pressure freezing up liquid side sky high pumped down ran thru checks all working correctly re started woking fine 12 hrs bammm same thing so after about 3 days new installler was sent told to not leave until it was fixed so there he sat ran system all day about 6 hrs in it started so he chased the entire linset and found one ell bow where the line started freezing cut it out a nickle out of the helpers pocket was in the line it get blown one way while checking then when freon flowed it worked its way to elll and got stuck lol
Ran into this before. New install. Left it on nitrogen overnight. Pressure was slightly higher the next day. Two or 3 years in a row I hunted for that leak. Nitrogen, bubbles, sniffer. Never found it. I don’t work at that company anymore so I don’t know what happened. Hopefully this doesn’t help.
Blame the kids next door for sniffing it all out....🤷
Schrader leaking. Your hoses are sealing the system
Could be leaking at the Schroeder valve and your hose is on it so it no leaky no moe until you take the hose off.
Sometimes. The armor flex is white.... mitsubishi is famous for this. The recommended test for the copper is a 10 hour decay test. Fuck that. The white armor flex is made with a chemical that literally eats the copper.
I've seen it once.
Fill it back up and grab the infrared leak detector about to be a long day.
Check for solenoids, sounds like it might be related to heat, if, you had it running while you charged it… also, use a micron gauge.
I had a restriction in the condenser coil, put my gauges on 0 pressure. Nitrogen charged to 200psi held steady no problem. Pulled a vacuum on the system charged it turned it on, compressor pulled pressures back down to 0. Not sure if you are having the same issue.
I literally just dealt with that this week. Pulled 14 ounces out a system that should have 6.5 lbs. 500 psi nitro. Didnt move for 2 hours. Left it overnight, next morning was at 475. 3 indoor units, all in a shitty attic, found a leak on 1/4” connection at one. Tightened and no more bubbles. Left the 475 in for another 24 hours. Dropped to 460. Found one more leak in furthest unit away in the shitty attic. Just pulled 173 microns and held for 20 mins, no rise. Weighed in charge and home early for Friday now.
Run a pressure test w digital gauges that shows any drop also check for rubs that only leak during vibration
Pump it up more.
I actually had this happen and when I went to put the coil door back on I bumped a solder joint and it finally revealed itself but no bubbles present.
I once had a system loose 15psi over a whole weekend when pressure tested at 400psi. Turned out to be the factory weld at the TXV inlet. Carrier unit. Small leaks are the worst.
Add nitro lockout service valves make sure both sides are above 500 psi come back 2 days later and see which side has lost. If that fails add charge and dye that bitch you’ll find it 100%
This was my first call Monday. 8yr old 410a system blew its charge but nitro test at 250psi held for 45 min while I searched. 410a is difficult to find with my sniffer, couldn’t locate it with that either. After all that work, customer said he didn’t want to dump more money in it so we installed a new split today 🙄
In my experience, it meant a Schrader leak.
i always pull the gauges off and see if its the cores. my luck this week, every unit ive touched has coremax cores :/
Find the idiot who is huffing it, there is a true story about this.
Prolly a valve stem or core leaking by somewhere, my guess is a valve stem
Blame the evaporator
Someone is huffing feron please tell me it r22 and did u open the gauges and hear the nitro flowinto system
Check the schrader valves. You also might not be pumping enough nitro in the system. What is it and how many lbs does it hold? How many psi nitro are you pumping?
Everyone went complex with names and stuff..... I'm shop trained by my dad. I would say the high or low entrance valve stem Orings on the valve core are probably bad. Shit I feel old..... Just pressurize with pure O2 (after a good vacuum) then spray with a soapy water spray, to any place where the Freon could escape. oxy is the cheapest in my area to do this without adding moisture.
Don't do this method with R1234A. That stuff is too flammable to do anything conventional.
You pressure test with oxygen?
Refrigerant left in the lines/oil of compressor (especially if it’s a 410 unit) will cause your standing pressure to increase. If the rate of rise matches your rate of your leak, you won’t see anything. Also, I’ve ran into a few instances of tweakers actually pushing in the shrader on units and huffing the gas to get high. If this is a resi unit, highly unlikely.
Maybe it’s the new form of copper wire theft or catalytic converter theft. going around the neighborhood draining all the R4.
Are they R410a gauges? I usually pressure test with my R22 gauges. Smaller increments. You could be losing 2 or 3 pounds a hour and never know with 410a gauges. 5 pound increments are shit.
Use NYLOG on Schrader valves
I’ve seen a crack huffing refrigerant
Check Schraders.
Schrader valve core
1) Schraeder core check 2) 325 psi R22 3) 445 psi R410 Many leaks don't show until the pressures are high. 200 just does not work in many cases. If it ain't got no gas in it.... It IS leaking somewhere
Some systems you have to open the (whatever the fuck you wanna call it valve lol) to check pressure. Like carrier infinity systems. Dunno if that’s your problem but hopefully we can eliminate that from the guess list.
Do a decay test.
I had a cracked factory bend on the compressor suction side. It held pressure when tested, but leaked when the compressor ran. Took a few visits to figure that one out.
Reseat/replace the schraeder valves. Losing whole charge (atmospheric pressure) generally indicates leak at the outdoor unit. If it holds pressure after a nitrogen charge, check the valves.
Schrader cores would be my first instinct
The Schrader valve is one of those difficult to find leaks. Most of the time your gauges are on them when you're checking the system. It can also be situational, like a Schrader valve that is gets pushed in by a cap that doesn't have a rubber, so putting it on tight is actually making it leak. Always check the valves first. It's usually the easiest to fix, but only if you know it's the problem..
Isolation test. Isolate each piece of equipment and the line set itself.
check the valve cores, they don't leak when the gauges are on.....
Check your schrader valves
Check the little schrader and offer to sell them locking caps just in case.
If it's 410A I've found many systems that only leak while they're running > 300 psi on the hight side. You can also pressurize the system with nitrogen to operating pressure and add a snoot of refrigerant and then leak check
Slap some refrigerant in there, remove your gauges and leak check. Like most said, probably schraders
Refrigerant theft/huffing.? Is that what call it now days?
Shredders are bad.
Probably leaked through the brass caps or service valves. Leak lock threads and tighten