Suction side Air leak from skimmer line

duraleigh · Apr 16, 2020

Have you opened and inspected the 3-way valve that allows you to select your suction source?

Pump running and as you begin to move the selector towards the skimmer, do you notice a drop in psi? It should be pretty big.

To complete the picture, what is your normal psi and what does it drop to when you move the selector to suction.

duraleigh · Apr 16, 2020

I looked back and can't find it.......did you check the pump basket lid and gasket? An ill-fitting gasket could possibly show those symptoms.

rp7777 · Apr 16, 2020

duraleigh said:
Have you opened and inspected the 3-way valve that allows you to select your suction source?

Pump running and as you begin to move the selector towards the skimmer, do you notice a drop in psi? It should be pretty big.

To complete the picture, what is your normal psi and what does it drop to when you move the selector to suction.

Yes I have opened the 3 way valve. I changed all the o rings and lubed them. I flooded it with a hose while the skimmer line is fully open.
Am I checking the psi gauge on the filter?

duraleigh · Apr 16, 2020

Am I checking the psi gauge on the filter?

Yes, it should be a lower pressure when you are drawing from the skimmer....perhaps as low as zero. I would it expect it to be 12-18 or so when there is no air in the basket (drawing from the main only)

rp7777 · Apr 16, 2020

duraleigh said:
Yes, it should be a lower pressure when you are drawing from the skimmer....perhaps as low as zero. I would it expect it to be 12-18 or so when there is no air in the basket (drawing from the main only)

Keep in mind I have a variable speed pump:
At 1700rpm
Main drain open running reads 5psi. the basket is full of water

Turning the valve to open only the skimmer still reads about 5psi but the basket gets about 1-2in of air.
Adding 1-3 hoses will pretty much empty the basket of water and the psi will drop to 0 psi

at 2850 rpm
skimmer open reads about 12psi
Skimmer with 3 hoses and the vac attached reads 0 psi and pretty much empty basket. Then it struggles to prime collecting water but immediately empties out out. Never gets more than a 1/4 basket full of water.
Main drain open reads about 15psi and is full of water

rp7777 · Apr 16, 2020

Next failed attempt which I knew was a long shot. I have a new pump but just to absolutely confirm my lid and o ring had a full seal, I basically bagged around the basket and taped it to the sides a couple of inches below the lid of the pump and then filled the makeshift bag with water. The purpose of this was to completely submerge the lid and see if it would eliminate any air while using the skimmer and a pool hose attached. The technique worked and held water but but I could still see the basket getting air proving that air was not coming in anywhere from the lid. Yes, I could have bought another o ring but the pump is less than a week old and I pretty much knew that was not the issue. 5 minutes of taping plastic and sealing was worth it to rule out one more possibility for the cause of the air in the basket

jimmythegreek · Apr 16, 2020

Unless you wanna try leak detection the only thing left is to make a plug with a threaded end on it and screw it into the skimmer threads. You may be able to use a quality test plug if you can find one. Then cut the PVC for skimmer line in a spot where re attachment or a union is easiest to re attach later and make a pressure test rig or buy one ready to go. Use am air compressor to do a low psi pressure test and add pressure slowly til you find the leak or hear it. A stethoscope works well for probing under the deck or dirt you can usually hear the leak

rp7777 · Apr 16, 2020

My skimmer pipe does not have any threads. Just a bare 1 1/4 in pipe where I insert the hose. I’m not against rigging up some low pressure testing device but would a stethoscope really work to listen to pipes buried 2 ft under concrete or soil?

jimmythegreek · Apr 17, 2020

Sometimes you can hear it without them if you can get some pressure in the lines. The water left in them bubbles pretty loud. I have a stethoscope in my tool bag. Leak detection uses the sound to find the leak in a more advanced manner but same idea

rp7777 · Apr 17, 2020

Last night I primed the pump then turned it off and opened the valve to the skimmer. This morning the pump basket was still full. I have no idea if the helps to validate whether or not the skimmer pipe has a leak or not. Just grasping at straws at this point

rp7777 · Apr 18, 2020

Today I attached each of the pool hose skimmer adapters in shown in the photo. just placing one of those even without a hose attached causes air to enter the pun. Even the small white one causes air to enter the pump. I barely place them and let the suction pull them in to the skimmer pipe.There is plenty of water in the pool so it’s not creating a vortex of air from the top. Could there be a crack in the skimmer pipe?

jimmythegreek · Apr 18, 2020

There is likely a break in the line somewhere. Usually at a fitting probably due to settling underground.

RDspaguy · Apr 19, 2020

Just found this thread. Sorry I missed it.
First off I must say, as a professional with 25 years of experience, well done sir. I have known only a few people who have such troubleshooting ability. I applaud your ingenuity.
And unless you failed to mention the large puddle around your pump after you left it off, which I seriously doubt, you are correct in your diagnosis. You have a suction leak in the skimmer line.
I have encountered several of these at the skimmer fitting itself. When the backfill settles (every pool builders nightmare) it drags down on the pipes. Pvc is semi-flexible side to side, but it does not stretch. The material of the skimmer is quite thin compared to the pvc walls, and the glue may or may not be srong enough to hold. So it either lets go at the glue joint (if they poured or shot under the skimmer), or it cracks out at the skimmer bottom around the glue fitting.
That may or may not be what you have going on. I have used the "giant stethoscope", as well as a few other means of leak detection, and can tell you that leaks can happen anywhere for any number of reasons. But this one is easy to find and easy to fix, so worth checking out.
It should leak minutely when the pump is off, so a dye test in the skimmer will reveal it. The dye should go outside of the pipe, if it goes inside the pipe your problem is farther back and you need to pressure test. But if this is your problem you will pass a pressure test with the skimmer plumbed as you describe.
A scrap of emery cloth and some epoxy will fix it up until it settles more and breaks again. Or you can dig out and replace the skimmer... but most people choose epoxy for some reason.
Sorry for the book, covid-boredom setting in.

rp7777 · Apr 19, 2020

jimmythegreek said:
There is likely a break in the line somewhere. Usually at a fitting probably due to settling underground.

I guess so. I just don’t understand how a small fitting literally about 2 inches tall just dropped into the skimmer pipe causes such a problem.

rp7777 · Apr 19, 2020

RDspaguy said:
Just found this thread. Sorry I missed it.
First off I must say, as a professional with 25 years of experience, well done sir. I have known only a few people who have such troubleshooting ability. I applaud your ingenuity.
And unless you failed to mention the large puddle around your pump after you left it off, which I seriously doubt, you are correct in your diagnosis. You have a suction leak in the skimmer line.
I have encountered several of these at the skimmer fitting itself. When the backfill settles (every pool builders nightmare) it drags down on the pipes. Pvc is semi-flexible side to side, but it does not stretch. The material of the skimmer is quite thin compared to the pvc walls, and the glue may or may not be srong enough to hold. So it either lets go at the glue joint (if they poured or shot under the skimmer), or it cracks out at the skimmer bottom around the glue fitting.
That may or may not be what you have going on. I have used the "giant stethoscope", as well as a few other means of leak detection, and can tell you that leaks can happen anywhere for any number of reasons. But this one is easy to find and easy to fix, so worth checking out.
It should leak minutely when the pump is off, so a dye test in the skimmer will reveal it. The dye should go outside of the pipe, if it goes inside the pipe your problem is farther back and you need to pressure test. But if this is your problem you will pass a pressure test with the skimmer plumbed as you describe.
A scrap of emery cloth and some epoxy will fix it up until it settles more and breaks again. Or you can dig out and replace the skimmer... but most people choose epoxy for some reason.
Sorry for the book, covid-boredom setting in.

Thank you for you reply and believe that I understand the covid boredom setting in. This pool issue has helped keep me busy during quarantine life and it also become an obsession.
What do you mean you have you used a giant stethoscope? Is this an Pool industry tool? I actually used a medical stethoscope from a first aid kit to listen to sounds from the ground. Surprisingly enough I was about to hear water so of course I started to dig. I knew it was a section where the pipes turned 90 degrees from the long grass straight run to the turn under the concrete deck. It turned out to be just the the noise of the water and air making the 90 degree turn. I then flooded it with water but the pump still did not fill with water. It’s now one more section of pipe/joints I can confirm where there is no break. Next step was to just finish exposing the skimmer pipe all the way to the back to the pump and then flood that as well. I was really looking for another joint but it turns out the builders used 1 long pipe. Unfortunately I didn’t realize it until I got near the pump trench and notice a joint that had had been exposed from a few days earlier. I could see my 2014 Home Depot pipes and the old pipe with the writing the matched the old pipe from the other end 15 ft away near the turn into the concrete deck. I did all the work so it was flooding time again. The whole pipe except under my pavers were exposed. I proceeded to flood the entire trench but I still have air in the pump. I can now officially confirm no breaks in the skimmer pipe the entire length of the grass.

dye test question. I’m not sure how to perform the test. Do I turn of the pump and just drop dye around the edge of the skimmer pipe and see if the dye sucks in the pipe hole or see if the dye gets sucks in between the pipe and the actual skimmer? I guess I'm understanding as write this.
Here are some more photos of my covid Pool project

RDspaguy · Apr 19, 2020

For leak detection there is a device that someone mentioned earlier that I always called "the giant stethoscope" because that is basically what it was. They cost thousands, your way is fine.
For a dye test you want no water movement at all. Not even a ripple. Drip your dye in near one side and watch closely. It will sink and spread, if there is water movement it will stretch out in lines toward the leak point like an arrow. Use leak test dye, not phenol red, coolaid, or any other hacks if you want good results.

rp7777 · Apr 19, 2020

RDspaguy said:
For leak detection there is a device that someone mentioned earlier that I always called "the giant stethoscope" because that is basically what it was. They cost thousands, your way is fine.
For a dye test you want no water movement at all. Not even a ripple. Drip your dye in near one side and watch closely. It will sink and spread, if there is water movement it will stretch out in lines toward the leak point like an arrow. Use leak test dye, not phenol red, coolaid, or any other hacks if you want good results.

I bought a dye test kit. The dye just floats over the skimmer pipe and also floats near the top side edge of the pipe. I also inserted the small plastic hose adapter and added dye near the outside base. No noticeable movement of dye.
On a separate note. I turned the pump on for a moment and then stopped it and the skimmer blew out some bubbles but if I leave the pump on longer I can’t recreate the bubbles coming out of the skimmer when the pump is stopped

RDspaguy · Apr 19, 2020

Well, now you know. I would have expected to see some movement from it, either around the pipe or down it. Suction leaks usually leak water out when the pump is off. Maybe not much, but some. Try it again with your valves closed, might make a difference if it's farther down the pipe. I should have mentioned that in the first place, sorry.
Or time to pressure test. I have built test rigs for air and water, but the water one uses the drain king thing and you already blew one up.
Or go ahead and pressure test.

Pressure Testers and Open Plugs

Check out the deals in Pressure Testers and Open Plugs at Anderson Manufacturing Company, Inc.

www.leaktools.com

wireform · Apr 19, 2020

I recommend doing a pressure test from the the pump end and using a plug in the skimmer. Open the union by the pump and rig something up there maybe unscrewing the part from the pump and rigging up something utilizing the thread. This way you can play with the valve and try to listen where you have air escaping.

rp7777 · Apr 19, 2020

RDspaguy said:
Well, now you know. I would have expected to see some movement from it, either around the pipe or down it. Suction leaks usually leak water out when the pump is off. Maybe not much, but some. Try it again with your valves closed, might make a difference if it's farther down the pipe. I should have mentioned that in the first place, sorry.
Or time to pressure test. I have built test rigs for air and water, but the water one uses the drain king thing and you already blew one up.
Or go ahead and pressure test.

Pressure Testers and Open Plugs

Check out the deals in Pressure Testers and Open Plugs at Anderson Manufacturing Company, Inc.

www.leaktools.com

I closed the skimmer valve, Placed the white adapter in the pipe and injected dye.I can’t even tell if the dye is being sucked in or not. If it is, it’s definitely barely noticeable. That dye pretty much just floats around

Suction side Air leak from skimmer line

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