Air Leak suction side - Main Drain line - no water loss

BP Framp

Member
Jul 12, 2010
8
OK - I've been all over. Heres the pool & problem. 25,000 gallon liner. 7 year old pool and hayward 2.0 hp. the pump sits 3 feet above pool. One skimmer, One main line. Both come up and merger to jandy valve in front of basket/pump. For a while I was getting small amounts of bubbles, with both lines open and each one shut. No real issue - very minor bubbles in basket while the pump was on you could see clear through. when pump was shut off you could see a small bubble come up out of the line into the basket about every 4 seconds. pump never lost its prime. I figured it may be a small leak in the valve.

Now over the weekend - all of the sudden, there are lots of bubbles, cant see through the basket lid. If I turn the valve to close main line completely off (on skim only) - it is back to where it was (very small amount of bubbles). If I turn the skimmer line off - large amount of bubbles and it struggles to pull the water. And when pump is off large air bubbles up into the basket. no longer holds prime. The large bubbles stop if I close the main.
I am figuring a main line leak above teh water line and below the pump. So I need to know what and where and how to fix. I had the valve apart, lubed everything, i checked all abve ground connections, using the watertrick and no changes.
Thanks for any/all help.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,682
Sebring, Florida
I am figuring a main line leak above teh water line and below the pump.
Me, too. You've done a pretty good job of isolating the issue.

One clarification, I assume your "main" line goes solely to a main drain at the bottom of your pool...right?

From Your description, I would still suspect that valve. (it's a 3-way Jandy, right? Somehow, just turning the valve to the main position is exposing an air leak. So that means the leak has to be at the valve occurring ONLY when the valve is in the main position or it has to be in the exposed pipes that come from the main drain.

Sometimes, if you can get the pump quiet enough, you can take a 1/2" or 3/4" piece of PVC pipe and use it as a "stethescope" by placing one end of the pipe right up at the suspected spot and placing the other end to your ear listening for a suction sound. Usually, the pump is too loud for that to be effective but I wanted to mention it.

I believe the leak is where you think it is and closer inspection may help you find it. It's also possible for an undergorund broken pipe but that's pretty rare.
 

BP Framp

Member
Jul 12, 2010
8
Thanks duraleigh. Yes - the main only has the main. and yes 3 way jandy. It air leaks a lot when both supply sides are open and also just the main is open. So I am figuring it is not the valve. Doesnt leak at all (very very minor) with the skimmer sucking. I cant imagine where above ground it would be. If i leave both supply lines open and i turn the pump off - it takes about 6 to 7 seconds for the large bubles to move into the basket. So I am figureing the break/leak is a few feet undergound. Is there any chance it is not undergound ?
 

Melt In The Sun

TFP Expert
LifeTime Supporter
Oct 29, 2009
3,899
Tucson, AZ
Sure; it doesn't have to be underground. Another quick trick that sometimes works is to run the hose over all the above-ground joints. If the bubbles lessen or go away, you've found an air leak. The fact that this suddenly developed in the middle of summer suggests to me that maybe the above-ground plumbing got bumped and something cracked, but that's just a guess.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,682
Sebring, Florida
Is there any chance it is not undergound ?
Yes, but you seem to be narrowing the possibilities.

You want to be sure there is NO chance whatsoever of it being above ground before you start to dig, however.

How many elbows, joints, unions, etc. do you have between the valve and the point where the pipes emerge from the ground? Do they all look good?..

For an underground leak to suck air, it has to have a pretty viable air source. Usually, the water that leaks out when the pump is off pretty much seals a leak buried in dirt but not in rock. Have you had any concrete settling that may have cracked a pipe?

Of all the suction side leaks posted here on the forum, I'd guess maybe 95% are above ground so you may be one of those 5% folks! :( :(
 

BP Framp

Member
Jul 12, 2010
8
Thanks to all. there is only one 90 elbo and 1 foot of pipe above ground. Everything else is below and its all dirt - no rocks. I checked the drain and nothing there. I have not pulled the 2 screws to take cover off. I guess I can check that, but i dont know why i would get bubbles up that line with an obstruction. i tried the water trick and nothing has been disturbed. The only thing I just found out was the kids had water balloons in pool - but of course they claim they all popped and are accounted for. i looked in th basket and found no pieces. and there is no way an intact balloon sunk and went in the drain cover. So I guess I am lookin at digging. I was also thinking of using that liquid stop leak. I was thinking of plugging up the main drain, then dumping the liquid stop seal down the pipe toward teh main.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,682
Sebring, Florida
Puzzling.

JohnT's idea of a clogged line makes perfect sense because of the sudden nature of the change.

However, John, I can't quite follow how air would get into that main line after the pump is off....so much so that it unprimes the pump.

I could only see that if BP is misdiagnosing the source of the air bubbles and they are coming from the lid and not the maindrain pipe. Do you see what I mean?
 

BP Framp

Member
Jul 12, 2010
8
Thanks John - I originally though maybe clog - but thats why I kept cycling pump. and when off the bubbles float to the surface. I eventried to just leave the main on a very little while the pump is on and still get massive bubbles. only stops when completly off.
duraleigh is kind of what i was thinking.
 

ride525

Gold Supporter
Jun 17, 2010
316
Pleasanton, CA
BP,

I've had a ball (or something similar) clog my intake line to pump. I took off pump strainer lid, and strainer basket, and ran garden hose back towards pool. I turned the water on, and I somewhat "sealed" area between hose and intake line with a wet towel. This worked pretty well on my 1.5" piping. I had ball pop back out at the skimmer.

I could see and feel water flow back out the skimmer. You might need two people, to do this, one to hold the towel and hose, and one to look and feel for water out the skimmer.

Hope this helps,

Jeff
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,682
Sebring, Florida
Jeff,

Despite it sounding as if it should be a clog, I don't think it is. A clog would not unprime the pump when the pump stops running.
 

ride525

Gold Supporter
Jun 17, 2010
316
Pleasanton, CA
duraleigh said:
Despite it sounding as if it should be a clog, I don't think it is. A clog would not unprime the pump when the pump stops running.
I'm not sure either. Just offering a quick way too check the suction line for a clog.

Jeff
 

BP Framp

Member
Jul 12, 2010
8
Thanks ride. Any input of ideas could help especially since it sounds like i need a stinking shovel, or a contractor.

I am actually thinking of putting a small ball on a string and dropping it down the open main line to see how far it goes so i have an idea but I guess it would go all the way to the pool water line. Any thoughts ????

Anybody else ??? yes - i want input - even if you think i need a shovel.
 

ride525

Gold Supporter
Jun 17, 2010
316
Pleasanton, CA
BP,

Try the garden hose with a towel after taking out the pump strainer lid and strainer. I would hate to see the ball come off the string, and get stuck somewhere.

Jeff
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,421
Pleasanton, CA
BP Framp said:
I am figuring a main line leak above teh water line and below the pump. So I need to know what and where and how to fix. I had the valve apart, lubed everything, i checked all abve ground connections, using the watertrick and no changes.
Thanks for any/all help.
That's the only thing that makes sense to me. But given your configuration, there should be more bubbles when the pump is on vs off. Is that the case?

I also agree with Dave that a clog would only cause air bubbles when the pump is running.
 

BP Framp

Member
Jul 12, 2010
8
Thanks mas and ride.

after diggin for a while i have an update.... about 2 feet down in teh dirt i found a sleeve where some brain surgeon apparently joined a 1.5 pipe from thr main to the 2 in - after i saw that - i filled the hole with water and now NO MORE AIR....only water - no bubbles, so i guess it finally just decided to leak, so now i just have to expoxy patch it and hope.....Thanks to all
 

ride525

Gold Supporter
Jun 17, 2010
316
Pleasanton, CA
BP,

Glad you found the problem.

I assume you have PVC pipe, correct? Why not just cut out the sleeve, and replace, rather than patch? You could do it with a 2" coupling, and a 1.5 to 2" bushing. The 2" side of the bushing slips into (inside) the 2" coupling, and the 1.5" side of the bushing slips onto (over) the 1.5" pipe. Lowe's has them. Here is a picture of the bushing:

http://www.lowes.com/pd_23310-1814-PVC+ ... 2727&Ntt=2

Jeff
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,682
Sebring, Florida
Ditto on the bushing. I would not use epoxy.

I'm glad you found the leak....even if you had to defy the odds and have it be underground, at least it appears it wasn't under the concrete.