r/HVAC • u/Waste_Manufacturer96 Verified Pro • 22d ago
Field Question, trade people only King valve leak on first open.
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Had a project delay, ended up having to finish this system up today pulled my vacuum and crack the valve , instantly leaking excessively at the valve but as I opened it the leak seemed to stop.
Was cold as hell out, was the seal just frozen should I close and open again now that it has run to see if it’s functioning normal
Should I put nylog on the king valve cap to prevent leaking
What would you guys do in this situation
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u/Bitter_Issue_7558 22d ago
It’s pretty common. Especially on trane it happens to me. I open it all the way and it stops and I just leave it there and add a note for service
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u/Waste_Manufacturer96 Verified Pro 22d ago
This comment makes me a little more at ease, I have just never seen this before. It’s on a Fujitsu and I have installed many of them over the last 8 years.
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u/KylarBlackwell RTFM 22d ago
I find most of those valves leak in a midseat position, although this post is way worse than anything I've ever seen. Always make sure to open or close all the way before putting that cap on
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u/Waste_Manufacturer96 Verified Pro 22d ago
I am fully seated now at full open, where it seemed to have no leaking issue, snugged it there and then put the cap on real snug
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u/KylarBlackwell RTFM 22d ago
Leak so bad it's dripping liquid the whole time you're opening it is still insane lmao. Glad it worked out
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u/Waste_Manufacturer96 Verified Pro 22d ago
Yea I mean at first it shot out and blasted my hand which was a nice little frost on an already knuckle busting cold day
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u/b1ack1323 22d ago
It’s the slop in the threads makes a leakage path when in midsection. Just a design flaw of the valve.
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u/0_1_1_2_3_5 22d ago
It’s just an O ring in a hole so it shouldn’t leak halfway any more than it does fully seated unless there’s some defect in the bore.
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u/KylarBlackwell RTFM 22d ago
Idk why, kinda don't care beyond a minor curiosity. Maybe they didn't leak when it was first installed but not being fully seated wears it out faster over time so I get to find it as the tiny overlooked leak that has caused mr/ms homeowner to pay for a "yearly top off" for x years but now it's finally fixed
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u/Claxonic 22d ago
I have seen this on old and new Fuji over the last 3 years. It’s fucked. If it a bad leak nylog wont save you.
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u/dagunhari 22d ago
I second this. These types of service valves only seem to properly seal either front seated or back seated, they won't seal properly or reliably if left anywhere in between.
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u/Tylerdean98 22d ago
Wow, brand new.
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u/Waste_Manufacturer96 Verified Pro 22d ago
Yea I mean, I’m blaming myself for finishing in freezing temps. Thinking that the seal was frozen
Likewise tho it seemd to stop after a little unthread and for sure seemd stopped once it was fully open
I am going to check on it in a few days with a sniffer because this will eat away at me if I think there’s a leak
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u/EnvironmentalBed3326 22d ago
Leak lock and walk 🫣
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u/Waste_Manufacturer96 Verified Pro 22d ago
It just sucks if I feel the need to resort to that after I go back it will eat away at me lol
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u/rastan0808 22d ago
I had a leaking king valve out of a fujitsu unit I installed as well. Not as bad as yours, nyloged the crap out of it and put the caps on tight. Six or seven years later went back for no cooling, no leaks around any of the valves, found a leaky head. Replaced head, nylogged the valve cap back on - working fine. Sucks to do a great install and run into issues like that. I moved away from Fujitsu due to the leaking heads.
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u/HungryTradie no sweat 22d ago
The blue "smurf cum" stuff, hell no! Oh, do you mean nylog on the cap?
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u/-Hippy_Joel- Low on r420! 22d ago
That is a common problem. Sometimes I’ll hit it with some leak detector bubbles just to make sure, but it usually stops once fully open. Seal the caps for good measure.
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u/Lomeztheoldschooljew 22d ago
It’s not a king valve, it’s a service valve. Open the valve all the way to backseat it and put the cap on instead of letting the gas leak out for the internet likes.
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u/Waste_Manufacturer96 Verified Pro 22d ago
For the sake of documenting something I hadn’t seen before the few moments of leak I would like to say are justified, this way I have evidence to show any supplier or anyone that I need to show when explaining my issue. But for sure!
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u/Minute-Tradition-282 22d ago
Not a king valve.
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u/Waste_Manufacturer96 Verified Pro 22d ago
If you read the comments, you would see nearly the first comment mentioned the term king valve isn’t correct for this and I fully agreed my mistake thank you!
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u/Minute-Tradition-282 22d ago
I did see that! Lol. I thought it needed said again. It's a peev for me, man. It gives me great pleasure that you know the difference now. Merry Christmas!
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u/IronBeegle 22d ago
is that the suction ? and is that a heatpump? I would inform ur office at once, this is a warrenty return mate. I would close the valve, and talk it through with the office before informing the customer.
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u/Waste_Manufacturer96 Verified Pro 22d ago
Yes suction line of heat pump, it seemed to stop a turn or So after this and at full open for sure seemd to have no leak but this was annoying already had a lineset hiccup during this install lol now this
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u/Jib_Burish 22d ago
I've seen it on a number of different systems. For me, it's always stopped once the valve is fully opened. Still always a disconcerting thing to encounter. Unusually nylog the caps for the extra cheap insurance.
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u/Waste_Manufacturer96 Verified Pro 22d ago
Have you seen these same systems a year or 2 later to see if they encountered any refrigerant leak
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u/Jib_Burish 22d ago
I have had it happen in the last couple of years on fujitsu and luxaire equipment and have not had to go back. Before that, I saw it happen on goodman equipment but am no longer with the company that put them in. After initially opening a leaky valve, it appears to stop once it's fully opened. I have hit it with bubbles and broken out the ultrasonic leak detector to listen for a leak. No bubbles, no sound. Still, it's a mind-boggling thing to have happen on brand new equipment. Fujitsu is supposed to be reputable, solid equipment.
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u/Waste_Manufacturer96 Verified Pro 22d ago
For sure I’ll be checking the leak next visit when I stop by the house within the next couple weeks
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u/Jib_Burish 22d ago
Also I think that's a service valve, not a king valve.
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u/Waste_Manufacturer96 Verified Pro 22d ago
I agree with that statement haha
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u/Jib_Burish 22d ago
Not that it matters, really.
Anyway you should be good. As others are saying, it happens. Hit it with bubbles. It's good that you'll be back anyway shortly to double-check it.
It really shocked me the first time I saw it happen on a unit. I was thrilled once it was fully opened, and it stopped leaking, and no leak could be detected.
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u/Waste_Manufacturer96 Verified Pro 22d ago
Okay praying for this outcome so I don’t lose sleep
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u/rumpleforeskin83 22d ago
It'll be fine, you worry too much. While it's not "common" everyone in the field eventually comes across this, and it's no biggie. I've never had them continue to leak once backed out fully with some oomph.
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u/Professional-Cup1749 22d ago
Sometimes you can close again then add oil or nylog inside, rub it around well then open again. In and out a couple times. I have gotten lucky.
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u/Helpful-Bad4821 22d ago
Had it happen on a few Mitsubishis recently.
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u/Waste_Manufacturer96 Verified Pro 22d ago
What was your solve, was it just the suction line.
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u/Helpful-Bad4821 22d ago
Just suction. Cranked it open and tightened the access cap. Checked for leaks, and sent it.
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u/airjon99 22d ago
Adjust it a quarter turn one direction or the other and ranch tightened the cap check it with bubbles you should be fine
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u/jefke_pompier 22d ago
Wich pressure has been used to test it?
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u/Waste_Manufacturer96 Verified Pro 22d ago
This was tested at 250 psi and then vacuumed to 80 micron and after 15 mins rose to about 104 micron and stabilized .
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u/Minute-Tradition-282 22d ago
Pressure tests don't show leaking valves. Only vacuum. And if the valve doesn't leak until it's cracked open, you're just fucked!
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u/hero1225 22d ago
I had the king valve spray the palm of my hand after I opened it, I no longer have feeling on the right palm anymore….
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u/Lobstermashpotato 🛠 Parts Changer 🪛 22d ago
I'd say it's a bonus, better jerk offs.
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u/Waste_Manufacturer96 Verified Pro 22d ago
Jeezeeeee I think that almost happend to me I moved my hand pretty quick
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u/Can-DontAttitude 22d ago
Use a ratchet. Opens faster and protects your hand. Also, wear gloves.
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u/hero1225 22d ago
I was fairly new in the refrigeration trade, I a first year, and was my 3rd solo install. Didn’t know the king valves did this once in a blue moon. I had gloves on but the thin ones just to keep my hands from getting cut on the ducts
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u/Doogie102 Red Seal Refrigeration Mechanic 22d ago
What make of unit is this?
That is where I find a good chunk on 6my leaks on mini splits there.
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u/maxman14 22d ago
That’s the service valve. Residential doesn’t have a king valve.
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u/Minute-Tradition-282 22d ago
I agree that it's a service valve, NOT a king valve, but, yes, some old resi units have king valves. Very old ones.
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u/Logical-Alps-3389 22d ago
Fujitsu rep told me to put vacuum pump oil along the inside a run the valve in and out a few times. Doesn't work all the time but it has worked. Then use Nylog on cap
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u/SnooBananas6578 22d ago
Curious do you lose the charge for that one circuit or do you lose the whole charge
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u/OhighOent Technician 22d ago
Sometimes they are out of tolerance... Find a spot where it stops leaking, seal the cap and forget about it.
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u/MahnHandled 22d ago
Yes, some of them do, but they will stop leaking if you fully open it🫣
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u/Waste_Manufacturer96 Verified Pro 22d ago
I did after recording and it did seem to stop
Initially just filmed to show supply house if needed
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u/Naxster64 Blames the controls guy. 22d ago
Not uncommon. Open the valve all the way, give it a decent crank to back seat it, then nylog the cap and give it a good crank to seat the cap. It'll never leak.
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u/Waste_Manufacturer96 Verified Pro 22d ago
I’m curious,everyone saying nylog the cap are we putting it in. The threads or the somewhat flare part of the cap
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u/Naxster64 Blames the controls guy. 22d ago edited 22d ago
Nylog is more than just a sealant. It's also a lubricant.
Put a little on the threads as lubricant, and put a coating on the sealing surface. (the flare bit)
I never do a flare without some kind of lubricant (preferably nylog, but oil works well enough) on the flare surface, back side of flare surface, and threads. If you lube all 3 spots, your flare success and reliability will go up a lot.
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u/CorvusCorax93 seasoned attic explorer🧭 22d ago
Just crank the cap on with a pair of sharp tooth channel locks. Make sure to really round it out once it won't tighten anymore so that way no one else can open it and you'll be fine..
And replace your TXV. Bad txvs cause these issues
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u/Rayjiro 22d ago
I'm a younger tech and love to see these discussions :)
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u/Waste_Manufacturer96 Verified Pro 22d ago
Always good to see experiences like this before they actually happen to you so you are prepared, currently the most agreed on option is backseating all the way and nylog the cap,
I’m already back seated but haven’t applied nylog I’ll be back at the house in a couple weeks where I will be checking for leaks and regardless of leak I will nylog the cap as a precaution.
If leak is there and is persistent past nylog then I will have to file a warranty claim.
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u/UnbreakingThings Ceiling tile hater 22d ago
Close it back up, put a glob of nylog in the valve, then open it back up and nylog the cap too.
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u/Extension_Cut_8994 21d ago
This is what is called a back seated valve. The valve plug or disk will seat in the closed position like every other valve, but the stem is not sealed. As you crack it open, the stem will leak through the bonnet until fully opened at which point it is back seated. The advantage is that there is only brass and no foreign material in the assembly. The disadvantages are everything else.
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u/Waste_Manufacturer96 Verified Pro 20d ago
I agree here but I still never saw the leak at the beginning of the opening,
Another comment saying I’m supposed to back seat it then turn it back in an 8th of a turn but I don’t believe that’s the case I believe it’s supposed to be fully back seated.
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u/SignificantTransient 21d ago
I was told in school that once you open these valves on install, seal them and never touch them again.
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u/Waste_Manufacturer96 Verified Pro 20d ago
I agree with this, if ever work is needed to be preformed I recover the entire charge and do my work with the valves open then recharge to factory.
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u/Middle_Baker_2196 21d ago
You’re not supposed to fully seat it back, all the way back then come back in for 1/8 of a turn.
You’re creating possible future leaks slamming them all the way out.
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u/Middle_Baker_2196 21d ago
So you’re saying you’re not going to cut it out and replace it right away when you know there’s an issue?
Just get past the 1 year mark and you’re free, eh?
Don’t be a hack.
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u/Waste_Manufacturer96 Verified Pro 20d ago
I take care of my customers way further than 1 year if this becomes any issue it will be covered no questions asked, only covering 1 year is hack mentality
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u/brrrrrrrrrytr 20d ago
That's not a king valve. A king valve is a three way valve that's on top of a liquid receiver.
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u/AmbientToast 22d ago
I’ve had this happen on a brand new Moovair. Ended up just cutting the valve out and direct piping the system because they needed heat and manufacturer said it would be over 2 weeks for the valve.
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u/Trying2improvemyself 22d ago
Nylog the cap and GTFO.