Suction side leak ... Help me problem solve this please. (Solved)

[Brazillianguy]

Hi everyone,
So recently I've noticed small bubbles in my return jets. It appeared to have been getting worse over a few months. Background of the pool is that it was resurfaced (diamondbrite) about 1 year ago and a better skimmer was installed. Also current pump (which came with the house when purchased 4-5 yrs ago) appears to be a Pentair Sta-rite Dura-glad housing with a Century 0.75 HP motor). When I went to my reading here and the internet I realized that since there were bubbles in my pool pump lid and no obvious leaks noted that I had a suction side leak. Things that I have checked and done.
1) Pool level is midway up skimmer opening and no debris blocking flow of water flow into the skimmer
2) Completely replaced O-ring of lid (lubed with Hayward silicone pool lube)
3) Checked and replaced 2 drain plugs with O-rings (lubed as well) . Since one didn't have an O-ring on it. But this didn't change the issue.
4) Lubed and checked the union O-ring (the one prior to the 90 degree entering the pump) and it seemed ok.
5) Noticed that when the Main drain valve (Pentair 1.5-2 in 2 way diverter valve) was completely open and the Skimmer was shut off that the bubbles essentially went away... (barely any noticeable). The minute I opened the skimmer side a burst of bubbles would rush in. Not enough to loose prime but would slowly start to fill the top of the lid making it more turbulent.
6) I purchased a completely new Pentair diverter and just replaced the internal components (lubing the 3 o-rings) and placing it on the old housing. I did notice that one of the old small O-rings was warped and brittle and broke off. With the new components it swivels much better but still there is air when the skimmer diverter valve is opened.
7) As the valves were open, I tried pouring a steady state of water from a hose over the diverter valve, pipe connections to see if it would diminish the amount of air being sucked in but to no avail.
8) I performed (to the best of my ability) a bucket leak check for 24 hrs to see if there was a leak somewhere in the pool, but in the 24 hrs no real major drop difference was seen.

I'm not sure what else to do. Could there be an underground leak on the skimmer suction side? Could the housing of the diverter be cracked or warped? From the diverter there is about 1-2 inches of pipe above ground before it goes underground. I spoke to a pool company (who briefly stopped by and will be coming by next Monday) and they said that if I had a crack underground that I would lose prime even if it was a small crack.

Will try to add photos to show the environment.

Thanks for taking the time to read and problem solve.

 

[Brazillianguy]

Here is the internal housing of the Pentair diverter (changed the cover and the the internal components)

 

[duraleigh]

I don't like the connection between the pump and the suction line (White to Black). That junction looks as if has been caulked........is that true?

 

[duraleigh]

Suction leaks are almost never in underground piping. They can be but it is extremely rare.

 

[1poolman1]

Hi everyone,
So recently I've noticed small bubbles in my return jets. It appeared to have been getting worse over a few months. Background of the pool is that it was resurfaced (diamondbrite) about 1 year ago and a better skimmer was installed. Also current pump (which came with the house when purchased 4-5 yrs ago) appears to be a Pentair Sta-rite Dura-glad housing with a Century 0.75 HP motor). When I went to my reading here and the internet I realized that since there were bubbles in my pool pump lid and no obvious leaks noted that I had a suction side leak. Things that I have checked and done.
1) Pool level is midway up skimmer opening and no debris blocking flow of water flow into the skimmer
2) Completely replaced O-ring of lid (lubed with Hayward silicone pool lube)
3) Checked and replaced 2 drain plugs with O-rings (lubed as well) . Since one didn't have an O-ring on it. But this didn't change the issue.
4) Lubed and checked the union O-ring (the one prior to the 90 degree entering the pump) and it seemed ok.
5) Noticed that when the Main drain valve (Pentair 1.5-2 in 2 way diverter valve) was completely open and the Skimmer was shut off that the bubbles essentially went away... (barely any noticeable). The minute I opened the skimmer side a burst of bubbles would rush in. Not enough to loose prime but would slowly start to fill the top of the lid making it more turbulent.
6) I purchased a completely new Pentair diverter and just replaced the internal components (lubing the 3 o-rings) and placing it on the old housing. I did notice that one of the old small O-rings was warped and brittle and broke off. With the new components it swivels much better but still there is air when the skimmer diverter valve is opened.
7) As the valves were open, I tried pouring a steady state of water from a hose over the diverter valve, pipe connections to see if it would diminish the amount of air being sucked in but to no avail.
8) I performed (to the best of my ability) a bucket leak check for 24 hrs to see if there was a leak somewhere in the pool, but in the 24 hrs no real major drop difference was seen.

I'm not sure what else to do. Could there be an underground leak on the skimmer suction side? Could the housing of the diverter be cracked or warped? From the diverter there is about 1-2 inches of pipe above ground before it goes underground. I spoke to a pool company (who briefly stopped by and will be coming by next Monday) and they said that if I had a crack underground that I would lose prime even if it was a small crack.

Will try to add photos to show the environment.

Thanks for taking the time to read and problem solve.

That epoxied fitting at the front of an improperly installed pump can be a source of a leak. Also, you may not have a leak at all. With that 90 directly into the pump you can get a form of cavitation in the fitting, actually separating the hydrogen and oxygen from the water into gas (bubbles).

A properly installed pump will fit the following (from PoolMagazine.com):
"One of the basic tenets of proper pool pump installations is eliminating elbows directly in front of the pump. The rule of thumb is to use a straight length of pipe 5-6 times of the pipe diameter (2” pipe = 10-12” straight pipe)."

Your installation would call for at least 7.5" of straight pipe into the pump. Yes, there are probably thousands of pools plumbed wrong that operate OK, but if all else is good on your pool it may be wise to look into that possibility. That epoxied fitting definitely needs to be replaced.

 

[RLP]

You said you had small bubbles in the return jets. Do you have them in the pump housing.?

Your SWCG will produce bubbles that you will see in the pool at the returns.

 

[Brazillianguy]

I don't like the connection between the pump and the suction line (White to Black). That junction looks as if has been caulked........is that true?

It was caulked initially (from when we bought the house and I noticed it when I I started looking for leaks). It was basically like melted thick glue when I would touch it. The first pool company that came to check out the leak put that epoxy on it to see about it sealing it. You know the funny part is that we bought this home from the owner (now retired) of a local pool builder/servicing company.

 

[Brazillianguy]

I'm going to show you pictures of inside the pump basket. One with the main drain valve open and the skimmer side closed (tiny bubbles noted). The other is with the main drain open and the skimmer open. I wanted to show the difference between the amount of air.

Side note I wanted to change out my pump to a VSP and I guess I would have them change out the pvc piping to make a straight connector to the pump.

Also when I have the main on and then open the skimmer side fully it takes about 4-5 seconds for that rush of air to come to the basket. When I start to close the skimmer diverter it sounds and feels like rocks rumbling in the housing of the diverter. not sure if it's bubbles... could there be something in the line?

 

[Brazillianguy]

Just updating things as I go along so it may help someone else. So from my reading and confirming on my pump and filter pressure gauge, I believe that I may have an obstruction in the skimmer suction line causing cavitation. I'm thinking this because when I love the diverter on the skimmer line it sounds like marbles or rocks rumbling around in it. Then I looked at the pressure gauge of the sand filter and it drops by like 3. This makes me think that the pump is attempting to suction from that line, but due to a (possible) obstruction it causes air to be formed (has to do with Vapor pressures blah blah... but there are good videos on YouTube showing cavitation and it's sounds and reasons.). My plan today is to use try to remove the obstruction (if it even exists). Wish me luck!

 

[Brazillianguy]

No solution yet. The pool company came out looked it over. He even took and small tear of a plastic bag and put it through the skimmer side (made me SUPER nervous) and it went straight through to the pump basket. He said that if it were an obstruction it wouldn't have gone through..... I guess... So he says that I might have a small leak in the underground suction side or like a fitting loose that's causing the air to come in the skimmer line. I'm not loosing water so that's the weird part. ANYWAYS!!!... I'm getting a leak detection company to come out and check it out. Even the Leak detection company said that this isn't normal and... hey you might be paying us a couple hundred for nothing.... I'm at a loss and frustrated.... hope an answer turns out. If anyone thinks of anything else and where to go from here I'd appreciate it. The only other thing is change the diverter even though it's not showing signs of a leak...

 

[RLP]

The first thing to do is eliminate the obvious. Pipe the pump per the manufacturer's instructions. Put a straight length of pipe in front of it as said above. Get rid of the epoxy or caulk or whatever it is.

A wise old guy once told me, after you do that, if it doesn't work, what are you going to do next? His point was do the easy, obvious, inexpensive stuff first.

 

[Brazillianguy]

The first thing to do is eliminate the obvious. Pipe the pump per the manufacturer's instructions. Put a straight length of pipe in front of it as said above. Get rid of the epoxy or caulk or whatever it is.

A wise old guy once told me, after you do that, if it doesn't work, what are you going to do next? His point was do the easy, obvious, inexpensive stuff first.

My question would be why would there be no air when the main drain is the only one open, but when the skimmer is open that's when the air is obvious. I'm not denying that the 90 degree elbow with it's epoxy or whatever they put on it was, but it that was a source of air entrainment, the air leak would be there as well with the main open only.

 

[Brazillianguy]

Just to followup and hopefully close the loop and maybe help others I just had the leak detection company out and there was a leak on the skimmer suction line. When they plugged the skimmer entry port (with the system off) the dye just got sucked up (instead of just being stagnate at the tube). Then after pressurizing the line bubbling came up. It was close to the pump. I'm thinking that the crack in the PVC was higher then the pool and would only drain up until that point and would stop right there.

 

[Brazillianguy]

Finally closing this issue. So there was a leak about 6 inches below ground at an elbow on the skimmer suction line close to the pool pump. I'm just thinking that this small crack was open enough to draw air in maybe a pocket surrounding the crack? But now that it's replaced, no more bubbles. Those with greater pool minds can maybe explain it since it's technically underground, but for those who can't find their suction side leak, this is a possibility.

 

[1poolman1]

Finally closing this issue. So there was a leak about 6 inches below ground at an elbow on the skimmer suction line close to the pool pump. I'm just thinking that this small crack was open enough to draw air in maybe a pocket surrounding the crack? But now that it's replaced, no more bubbles. Those with greater pool minds can maybe explain it since it's technically underground, but for those who can't find their suction side leak, this is a possibility.

Underground suction leaks can, definitely, pull air. As it is a water leaks when the system is off, the soil surrounding the pipe erodes away and you have a pocket of air around it. I've seen it many times.

 

[Texas Splash]

So there was a leak about 6 inches below ground at an elbow on the skimmer suction line close to the pool pump.

A lot of work I'm sure, but rewarding to finally get it. Good ob.

 

[duraleigh]

Yours is a good example of suction side leaks ALMOST ALWAYS being above ground but there are exceptions. 1poolman1 writes a good description of how the can occur.

 

[Jimrahbe]

BG,

What a pain!!

Thanks for the follow up showing the problem...

What did you have to do to fix it with very little room for an repair?

Thanks,

Jim R.

 

[Brazillianguy]

Underground suction leaks can, definitely, pull air. As it is a water leaks when the system is off, the soil surrounding the pipe erodes away and you have a pocket of air around it. I've seen it many times.

That's what I was thinking (about the pocket of air). I didn't really lose water in the pool so I didn't expect a leak. I wonder if maybe the angle of the skimmer suction pipe made it so that it wouldn't leak from the pool. Maybe being a little above the pool and it being close to the pump would leak water up until that crack. Another thought would be that my pump starts early (around 0600-0700) so maybe the pump basket is partially empty and when it kicks in pulling water and air (being too early from me to check the pump to see if it's partially empty before it started.) Just another thing to think about when problem solving.

 

[Brazillianguy]

A lot of work I'm sure, but rewarding to finally get it. Good ob.

My mind was completely consumed with trying to figure it out. Even one of the pool companies technicians was impressed with how much I knew.. even joked if I wanted a job HAHA!.