My first mechanical keg failure?

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ChickenRob

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Hoping someone here can steer me in the right direction. I built a kegerator for doing continuous seltzer, and I sent chilled still water from it as well. Got everything dialed in, and it was working great. I loved it. (Full build thread in soda sun forum).

It’s based on a corney keg feeding chilled water to a tap, and chilled water to a second keg with a kegland carbonator lid.

this week it started dispensing intermittently. I took apart the tap, but that wasn’t the problem. I couldn’t figure out where it was failing me.

Today it stopped working entirely. I chased it all the way back to the keezer. There was nothing coming out of the seltzer keg.

I connected a pressure gauge and short tube with a ball valve connector and connected it to the keg feeding the carbonation keg. No problem. Full pressure. I connected the gauge to the ball lock post on the carbonation keg. It read 42psi. This would be the pressure of the CO2 at the top of the keg. A little lower than my CO2 regulator, but close.

I then connected to the seltzer output post. No pressure. This is a brand newItalian made keg. Could this be a failed post? I’m not looking forward to lifting this keg out of the seeder while full and trying to figure it out. Any advice before I do it?

thanks again for any help.

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Deadalus

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Depress the poppet on the liquid post of the keg with a screwdriver and see if anything comes out of the post with no pressure? Or something softer than a screwdriver, you can scratch it.

Depressurize the system and remove the post. See if there is something wrong with it. Do you have another post you could connect from another keg that you know has the same threads?
 
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Deadalus

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I am wondering if your ball lock disconnect is fully seated on its post for the liquid out. The way you describe your pressure gauge is that you have it on a piece of tubing and you are inserting that into the push to connect side of the gray coupling (John Guest or whatever brand).

And did you take apart your disconnects and reverse the slotted caps? I don't think I have any where the color of the caps are opposite like that.

The disconnects are on the correct posts as well? Gray goes to gas in, black is for beverage (beer) out. The gas post is often marked with a gash.
 
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ChickenRob

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Those caps are how they arrived from keg factory. I did not disassemble them.

I have a spare ball lock coupler with a threaded push fit (all duotight) a piece of Eva barrier with a T fitting with a pressure gauge on one outlet and a ball valve on the other.

the gray coupler is the co2 in, the black is on the liquid out, the other black is the water in from the chilled keg in the carbonator lid.

The system worked perfectly for weeks. Then became intermittent, then failed.

I’ll get down there today and repress the poppet. I do have a spare keg from the same manufacturer I can swap in, I just have no good way to empty the keg since the water out post seems to be the point of failure. The ideas of lifting the keg full or working on it in the keezer both bum me out. I’ll depress the poppet and see what happens.
 
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Those caps are how they arrived from keg factory. I did not disassemble them.

I have a spare ball lock coupler with a threaded push fit (all duotight) a piece of Eva barrier with a T fitting with a pressure gauge on one outlet and a ball valve on the other.

the gray coupler is the co2 in, the black is on the liquid out, the other black is the water in from the chilled keg in the carbonator lid.

The system worked perfectly for weeks. Then became intermittent, then failed.

I’ll get down there today and repress the poppet. I do have a spare keg from the same manufacturer I can swap in, I just have no good way to empty the keg since the water out post seems to be the point of failure. The ideas of lifting the keg full or working on it in the keezer both bum me out. I’ll depress the poppet and see what happens.

You can easily disassemble a ball lock disconnect in order to inspect its workings (there's only a spring in there). Locate the large slot on the back of the disconnect and just unscrew. Very easy, but many don't know it's there. I doubt the problem is in there, but who knows. Seems more likely you've got fluid disconnect on the gas post, or something like that.

Good luck.

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Deadalus

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You wouldn't have to pull the keg out to begin diagnosing. I think something is potentially mixed up in the assembly of the keg. Given this constant feed, I wonder if you could potentially have the dip tubes mixed up. With continuous feed from the second keg, maybe the water filled the carbonation keg to the top of the keg and water is able to exit the gas tube length dip tube even if it was on the wrong post? The water has higher pressure than the CO2 regulator, which might have kept the water high enough for that to happen. Then maybe a pause or system change allowed the CO2 to create headspace. If there was kind of a "battle" between the two pressures maybe that headspace fluctuated. Just a thought and I can think of a way to test it. Bleed the pressure relief valve on the carbonation keg lid. If you release enough air, you might reduce the headspace enough to get flow again. Probably not the problem as nothing is reading on your gauge but an easy check.

Also, let's make sure the posts are correctly assembled. You are new to this and it's easy for some kegs to be assembled incorrectly. Take a picture of the top of the keg with the disconnects on. Remove the disconnects and take a picture of the top of the keg and posts. Some kegs will stamp an in and out next to the posts. Like I mentioned, there is often a gash, hatch mark on the gas post which goes on the in side. Sometimes the threads are different as well and the posts won't properly interchange either. Once you know which post is definitely which, take off the gas post and see if the gas dip tube is under it. If it is, then look at your first picture and make sure you had the gray disconnect on the gas post. If that is all good, then sometimes the liquid tube fits into a well at the bottom and sometimes this is better achieved for one post than the other. Not always the case and sometimes it doesn't matter. In your continuous feed situation, it wouldn't matter.

Ok about the disconnect tops being opposite colors. I didn't think it would have been possible to mix them up because you had different numbers of each but thought I would check. I don't think though that the spring and rod inside each are different in any way. However, the bases of the disconnects are different slightly to prevent mixing up the disconnects. One of the posts on a ball lock keg has a bump of sorts that makes it harder to put the wrong post on but it is not 100% foolproof. Sometimes people can get the wrong disconnect on the post. It pays to be extremely systematic with diagnosing these and only changing/checking each piece singly and not mix up pieces as you do it because with ball lock kegs the post differences are a little more subtle.
 
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Deadalus

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I will add I read through your build thread. I had never seen flexible pvc before, I didn't know it existed! I was checking it out last night and it appears it glues and fits just like regular PVC provided it is the same schedule. I built a tower kegerator and used a similar fan air flow but I used 1" ID vinyl tubing with barbed fittings. I don't like this tubing though as it has a propensity to flatten. I had a leak so I may improve the design and switch to that flexible pvc. I was using a tupperware container instead of an electrical box for the fan but it wasn't attached yet. I developed a leak up in the tower at a shank and have to disassemble unfortunately.
 
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ChickenRob

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Freezer is above freezing. It’s a chest freezer with an inkbird. A quart of water holds the probe. The chilled still water is flowing fine, but the seltzer is not. No sign of freezing anywhere.

I double checked the connections. Gray has thegas line going to the post marked IN, the seltzer feed is the black connect connected to OUT. The kegs are clearly marked.

I disconnected all the couplers and pressed the pins with a stiff plastic handle from asmall cleaning tube. The in and the water feed on the lid both released gas. The pin in the out connector depressed, but nothing, not gas or water, escaped.

Even if I had them connected backwards, all3 should register pressure on the fauge, but only 2 of them do. There’s clearly a problem with that pin. I hope these come out easily. About to find out…
 
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Freezer is above freezing. It’s a chest freezer with an inkbird. A quart of water holds the probe. The chilled still water is flowing fine, but the seltzer is not. No sign of freezing anywhere.

I double checked the connections. Gray has thegas line going to the post marked IN, the seltzer feed is the black connect connected to OUT. The kegs are clearly marked.

I disconnected all the couplers and pressed the pins with a stiff plastic handle from asmall cleaning tube. The in and the water feed on the lid both released gas. The pin in the out connector depressed, but nothing, not gas or water, escaped.

Even if I had them connected backwards, all3 should register pressure on the fauge, but only 2 of them do. There’s clearly a problem with that pin. I hope these come out easily. About to find out…
There's a little oring on the pin in the disconnect. I've never seen this happen, but maybe it became unseated and is clogging orifice in disconnect. Or some other clog.
 
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ChickenRob

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Well, I pulled a post off a spare keg I have, depressurized, swapped the post, and still no luck. Why? Because @Nate R nailed it I think. Freezing? I opened the keg, checked to make sure the tube was on the right side (it was) and saw just a little ice floating on the surface of the water. Inkbird was set at 35 with 2 degree differential. I figured the higher pressure still water keg or the much smaller 1 quart jar would both freeze before the seltzer keg.

I unplugged the freezer from the inkbird and am letting it warm up. Reset the temp to 37 instead of 35.

I loved how cold and carbonated the seltzer was. Any thoughts on keeping it cold and avoiding the freezing? A little insulation at the bottom of the keg and where it touches the freezer wall?

thanks for the help trouble shooting. I hope it’s just ice and I see it melt later today.
 

Deadalus

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Sounds like Nate got it, good call Nate!

You could pull the dip tube and see if it is clogged with ice, if it hasn't melted yet. The probe has a certain accuracy of plus or minus something as well.
 
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ChickenRob

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Sounds like Nate got it, good call Nate!

You could pull the dip tube and see if it is clogged with ice, if it hasn't melted yet. The probe has a certain accuracy of plus or minus something as well.

I figured I was safe as I have a couple thermometers that all read between 35-37 when I tested the water that came out at the keg after the first week of chilling things. I’ll see what happens, but I’d be surprised by a blockage since I thoroughly cleaned all the parts before installing and the water goes through both a whole house filter and RO system before entering the keezer. But that is the next thing if thawing doesn’t work.

The sink tap in the kitchen is already showing some pressurization though.
 
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ChickenRob

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And sure enough, it has melted and the seltzer runs free! Thanks for all the help!
 
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ChickenRob

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After only a few weeks of seltzer on tap, dialed to my personal preferences, it was amazing how annoying my favorite canned seltzer was as a backup.
 

Nate R

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Glad i could help!!

Also... for my freezer, if it is really full, things will freeze (and faster) than at the same temps if it is less full. Some science term applies here i bet.
Anyways- if i fill up my freezer i will just add a degree or two on the inkbird.
I like my beers cold (heretic, i know) so i just add or remove a fee degrees on the ole inkbird.
 
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ChickenRob

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Glad i could help!!

Also... for my freezer, if it is really full, things will freeze (and faster) than at the same temps if it is less full. Some science term applies here i bet.
Anyways- if i fill up my freezer i will just add a degree or two on the inkbird.
I like my beers cold (heretic, i know) so i just add or remove a fee degrees on the ole inkbird.
This is good to know. Since I’m just doing water and seltzer in this freezer, I have just 2 kegs total in a 7cu ft. I was thinking of adding a third for additional thermal mass to make it run more efficiently, and if I do, I’ll raise the inkbird a little first and then lower it slowly.
 

bruce_the_loon

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How is the air circulation in the freezer, there was a thread a while back where the addition of a small fan to circulate the air inside the freezer eliminated warm and cold spots that was causing kegs to freeze up while the temperature probe which was on the hump was reading a warmer spot.
 
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ChickenRob

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How is the air circulation in the freezer, there was a thread a while back where the addition of a small fan to circulate the air inside the freezer eliminated warm and cold spots that was causing kegs to freeze up while the temperature probe which was on the hump was reading a warmer spot.

I have a fan that blows cold air up a pvc pipe to keep the beverage lines chilled on their way tothe kitchen, andthat moves some air around pretty well, but I could add a second small fan pretty easily. I’ll do it since I have it. Thanks for the tip.
 

IslandLizard

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Reading all this, when you get close to freezing temps of water, 1-2 degrees can make all the difference between freezing up or not.

The bottom of a freezer/keezer tends to be the coldest, cold air is heavier and sinks, while insulation near the top (lid) is generally poor and temps are definitely a few degrees higher.

Correct probe placement in these critical temp systems becomes very important!
If your probe holding jar is placed on the hump, chances are it will not be even close to the temps on the very bottom. You'll need to find the best placement for the probe that actually reflects the temp in the bottom part. Many of us place the probe on a keg wall, on the bottom 3rd, covered by a piece of 1/4" packing foam to reduce ambient readings, taped, strapped, or bungeed to it. But that's for beer, not water, and usually not held at 32F.

I have a fan that blows cold air up a pvc pipe to keep the beverage lines chilled on their way tothe kitchen,
How long are those lines? You may lose much of that ice-coldness you're craving in your dispensing system. Insulate that well and you may be able to keep your kegs at 34-36F instead of closer to 32F.
 
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ChickenRob

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Reading all this, when you get close to freezing temps of water, 1-2 degrees can make all the difference between freezing up or not.

The bottom of a freezer/keezer tends to be the coldest, cold air is heavier and sinks, while insulation near the top (lid) is generally poor and temps are definitely a few degrees higher.

Correct probe placement in these critical temp systems becomes very important!
If your probe holding jar is placed on the hump, chances are it will not be even close to the temps on the very bottom. You'll need to find the best placement for the probe that actually reflects the temp in the bottom part. Many of us place the probe on a keg wall, on the bottom 3rd, covered by a piece of 1/4" packing foam to reduce ambient readings, taped, strapped, or bungeed to it. But that's for beer, not water, and usually not held at 32F.


How long are those lines? You may lose much of that ice-coldness you're craving in your dispensing system. Insulate that well and you may be able to keep your kegs at 34-36F instead of closer to 32F.

The line is 15 feet. I have an inner run of 1.5” flexible pvc carrying the drink lines and the chilled air runninginside a 2.5”rigid PVC pipe as an air return. The whole thing is insulated on top of this. This seems to be keeping things chilled. I’ll watch it for now. Put in a second fan, and if things freeze up again I’ll look into different measurement points for the probe. My goal is sun 40 degree water at the tap. I’m getting 41 now (which is good enough). I’ll test it at the keg and see what my temp loss ison the run from basement to kitchen.
 

IslandLizard

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The line is 15 feet. I have an inner run of 1.5” flexible pvc carrying the drink lines and the chilled air runninginside a 2.5”rigid PVC pipe as an air return.
That's fairly long. Are you blowing/recirculating cold air inside that 2.5" pipe 24/7?
Is that one way or is there also an air return pipe?
 
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ChickenRob

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It is a smaller pipe inside a larger pipe. The cold air and beverage lines run through the smaller pipe and then the air returns in the larger pipe. You can see my build thread here:

My seltzer keezer build

and yes, the air circulates 24/7.
 

Nate R

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It is a smaller pipe inside a larger pipe. The cold air and beverage lines run through the smaller pipe and then the air returns in the larger pipe. You can see my build thread here:

My seltzer keezer build

and yes, the air circulates 24/7.
Wow... that is great.
I just skimmed your post and i had two thoughts...
#1: this is great!
#2: all this work for just water?? Lol. I would only do this for beer! (But i bet you're healthier than i am!)
 

Nate R

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Correct probe placement in these critical temp systems becomes very important!
I agree... but am also a little lazy. When i built my upright 4-tap keezer i just placed the probe in an out of the way place. I built a three-level shelf with low cfm fans installed on each shelf.
After a little trial and error my temp is more or less set. Only have to adjust temps if i have all 4 kegs on the bottom. Otheriwse the low cfm fans help.
Never needed to put probe in water- i was worried about degradadtion on the probe in water. (But inkbird is always on sale here, and they are cheap enough).
 
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ChickenRob

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Wow... that is great.
I just skimmed your post and i had two thoughts...
#1: this is great!
#2: all this work for just water?? Lol. I would only do this for beer! (But i bet you're healthier than i am!)

#1 thanks!
#2 I’ve had some health challenges that have motivated me in my quest for clean water I enjoy. This seltzer system helps me drink a couple extra quarts/day.
 
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ChickenRob

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So I just went and tested the temps. After thawing it out yesterday and recoiling for a day. I’m at 34.5 degrees straight from the keg, and 38.1 degrees at the tap. 3.6 degrees seems like a big drop in a short time, but I think part of that is pressure helps chill things, so I drew a sample from the keg and let it sit about a minute. It was 35.1 within one minute, I suspect just from no longer being under pressure.

overall though, I’m loving the system and grateful for all the help from this forum.
 
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ChickenRob

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My water is under pressure so it carbonates. The side effect of putting something under pressure is that it cools it. It’s how air conditioner compressors work. Expanding them raises their temperature. It’s how heat pumps work. Im not sure how much any of that comes into play with a 47.5psi co2 line in a 5 gallon keg. Just speculation on my part.
 
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