Mysterious suction leak

[Bongfire]

Hi guys, can I get your advice on locating a mysterious suction side leak?

13k gal in-ground pool, 1.5HP pump, 25" sand filter, suction cleaner, no main drain, skimmer box goes to pump directly through a 2" pipe

Everything was working well until last year when I noticed large bubbles from the return jets. Now the water in the pump strainer is only 1/2 to 3/5 full, surging, and the pump loses prime when shut down. Bubbles continuously come out from return jets. Cleaner is not getting enough power and stops every now and then.

What I have checked:
- Water level at least 3" above skimmer
- Skimmer, pump strainer and filter are all clean
- Pump strainer o-ring replaced and lubricated
- Pump drain cap definitely sealed tight
- Pump suction side union o-ring replaced and lubricated
- Pump ceramic seal replaced
- Finally, whole pump replaced
- All above-ground pipe connections such as elbows and unions are tested with foam and cling wrap
- Turned MPV to recirculation position. No significant change.
- Removed suction cleaner and let water go into skimmer directly. Slightly better but pump is still not full and bubbles still exist

I don't know what else I shall try now. Can anyone please give some help? Thanks.

 

[Texas Splash]

Welcome to TFP! Well, you've done quite a bit already. I'm guessing you have no main drain to try pulling just from there? The only other thing might be a pressure test on that suction side to ensure there are no breaks. I will say though that even with foam and cling wrap, some air leaks can get by us. So before having someone do a leak test, I would consider dismantling any 3-way valves located before the pump to ensure the handle stem seals and top and in good shape. Hopefully something simple like that. Good luck!

 

[Jimrahbe]

BF,

I assume this is an in-ground pool, is that true?

Show us some pics of your pool and equipment pad.

What does the water in the skimmer do when the pump is running? Does the water get sucked out, then it refills, then repeats the sequence?

Thanks,

Jim R.

 

[Bongfire]

Welcome to TFP! Well, you've done quite a bit already. I'm guessing you have no main drain to try pulling just from there? The only other thing might be a pressure test on that suction side to ensure there are no breaks. I will say though that even with foam and cling wrap, some air leaks can get by us. So before having someone do a leak test, I would consider dismantling any 3-way valves located before the pump to ensure the handle stem seals and top and in good shape. Hopefully something simple like that. Good luck!

Thank you. There's no main drain. Skimmer box is connected to pump inlet directly with a 2" pipe, about 40' long, mostly underground. Also there is no valve between them. So the next step should be pressure test. Is this something that I can DIY ?

 

[Bongfire]

BF,

I assume this is an in-ground pool, is that true?

Show us some pics of your pool and equipment pad.

What does the water in the skimmer do when the pump is running? Does the water get sucked out, then it refills, then repeats the sequence?

Thanks,

Jim R.

Hi Jim,

Yes it's an in-ground pool. I'll take some pictures.

The water in the skimmer does not pulse or surge, and there is no air sucked in from there. I specifically put a brick on the skimmer basket when testing, to prevent vortex.

Thank you.

 

[1Sammy]

How is your cleaner piped in / attached ?

 

[Jameshtx]

Following
I've got a similar issue right now with air bubbles coming out of jets n also pump strainer half full

 

[Bongfire]

How is your cleaner piped in / attached ?

Thank you 1Sammy.
The suction cleaner is connected through a 36' hose to the vacuum plate. In order to rule out the leak in this part, I have removed the hose and vacuum plate, letting water go into the skimmer directly, but there is still air in the pump, and bubbles are still coming out from the jets. I'm 100% sure there is no air sucked in from the skimmer.

 

[Adwizard]

Hi guys, can I get your advice on locating a mysterious suction side leak?

13k gal in-ground pool, 1.5HP pump, 25" sand filter, suction cleaner, no main drain, skimmer box goes to pump directly through a 2" pipe

Everything was working well until last year when I noticed large bubbles from the return jets. Now the water in the pump strainer is only 1/2 to 3/5 full, surging, and the pump loses prime when shut down. Bubbles continuously come out from return jets. Cleaner is not getting enough power and stops every now and then.

What I have checked:
- Water level at least 3" above skimmer
- Skimmer, pump strainer and filter are all clean
- Pump strainer o-ring replaced and lubricated
- Pump drain cap definitely sealed tight
- Pump suction side union o-ring replaced and lubricated
- Pump ceramic seal replaced
- Finally, whole pump replaced
- All above-ground pipe connections such as elbows and unions are tested with foam and cling wrap
- Turned MPV to recirculation position. No significant change.
- Removed suction cleaner and let water go into skimmer directly. Slightly better but pump is still not full and bubbles still exist

I don't know what else I shall try now. Can anyone please give some help? Thanks.

I don't know if I can help you but a lesson I recently learned is that every one told me my air leak was on the suction side. As it turned out, it wasn't. It was on the return side. My pool guy replaced my salt water generator and it was leaking where he glued the pipes back together. On the return side. For days and days I never noticed because I had my pool heater running...and the condensation spread over my pool equipment floor and covered up the leak coming from my salt water hookup. Only when I turned off the pool heater did I realize the leak. Prior to that I glued all around every conceivable coupling and hookup. Replaced every O ring. Reprimed the pump day after day. Unneccesary. A painful lesson. Now my nice clean pipes look dirty because of the glue discoloration. Almost fired my pool guy. But I found the problem and my pump easily primed after refitting and re-gluing the leaky salt water generator. So, lesson learned; not always suction side. Two. Don't believe everything you read. Good luck.

 

[mknauss]

If air is being pulled into the system with the pump running, the leak is on the suction side. There is no way air can be pulled into the system on the pressure side -- with the pump running.

 

[Jimrahbe]

Don't believe everything you read.

@Adwizard,

I suspect you had a different problem.

With a leak on the pressure side, the pump will drain back into the pool when the pump is off. When the pump restarts, it will be full of air and blow huge bubbles out of the returns. Is that the problem that you had?

Thanks,

Jim R.

 

[Bongfire]

I don't know if I can help you but a lesson I recently learned is that every one told me my air leak was on the suction side. As it turned out, it wasn't. It was on the return side. My pool guy replaced my salt water generator and it was leaking where he glued the pipes back together. On the return side. For days and days I never noticed because I had my pool heater running...and the condensation spread over my pool equipment floor and covered up the leak coming from my salt water hookup. Only when I turned off the pool heater did I realize the leak. Prior to that I glued all around every conceivable coupling and hookup. Replaced every O ring. Reprimed the pump day after day. Unneccesary. A painful lesson. Now my nice clean pipes look dirty because of the glue discoloration. Almost fired my pool guy. But I found the problem and my pump easily primed after refitting and re-gluing the leaky salt water generator. So, lesson learned; not always suction side. Two. Don't believe everything you read. Good luck.

Thanks for your reply. Did your pool show the same symptoms such as bubbles coming out of the return jets?