Need Help with Suction Side Leak (w picture/videos)

tom496

0
Jun 27, 2013
10
We open the pool last weekend, and when I first ran the pump, things seemed fine. Some minutes later, though, there were a lot of bubbles and a large amount of air in the salt cell:
2017-06-09 23.53.15.mp4 - Google Drive

Also, the water level in the strainer pot stays about an inch below the top.
View from above: 2017-06-09 23.52.31.mp4 - Google Drive
Strainer pot and pump: 2017-06-09 23.56.50.mp4 - Google Drive

Here is my setup:
2017-06-09 18T.jpg - Google Drive

What I have tried so far:
  1. When I close the skimmer valve and keep the drain valve open, and vice versa, I do not see a change in the bubbling, so I conclude the leak is between those valves and the pump.
  2. Skimmer - the water level in the pool is high and there is no vortex in the skimmer, so the skimmer is not the source of the air in the system.
  3. Strainer Pot Lid - I removed and cleaned the silicone grease from the O-ring. The O-ring appears to be in like-new condition and shows no defects. I wiped the grease from where the O-ring seats on top of the pot and where it seats on the lid. Again, there are no visible defects and the O-ring fits snugly on the lid. I generously re-greased the O-ring and both of the seating surfaces. I inspected the lid itself for cracks or defects. I also tried intentionally over tightening the lid. None of the above affected the volume of bubbling.
  4. Strainer Pot Plug - I removed, examined and re-greased the plug and its O-ring at the bottom of the strainer pot.
  5. Ortega Valve - A couple of years ago I replaced the three O-rings and the barrel-shaped seal in this valve. (I think most pool owners have a Jandy Valve in place of this?) This week I replaced the three O-rings, the largest one having been damaged. I generously re-greased all seals and O-rings.
  6. Spa Side - Recognizing that if the Ortega valve is leaky, air from the spa return could be entering there, I also tested the connections and union on that side in the way described below. I would also note that when I turn the Ortega valve to the spa side so that water is being drawn from the spa rather than the pool, the volume of bubbles does not change.
  7. Connections and Unions - In the past I've had decent luck running water over connections and/or wrapping wet rags around connections and running water over the rag. When that failed, I tried shaving cream. When that failed I tried incense smoke. All of this failed to locate the leak or leaks. On the theory that maybe I had a lot of little leaks, I applied silicone grease to the soldered connections and unions, and where possible, tightly wrapped electrical tape over the grease. This also failed to reduce the volume of bubbles. (I tried these approaches at all points on the suction side, not just of the connections and unions.
  8. From reviewing posts in this forum, I saw that for some folks, the culprit was where the 2 inch pipe enters the strainer pot. I heavily greased that junction, and also attempted wrapping Teflon tape and electrical tape around it to try to achieve a reduction in bubble volume, to no avail. For some reason, I'm suspicious of that connection, but I cannot redo that connection without cutting out some of the copper pipe since there are no unions between the strainer pot and the three unions you can see that connect to the drain, skimmer and spa.
  9. There is no visible "spitting" when I shut down the pump.
I have not tried applying PVC glue to joints. I read that some folks had success doing that while the pump is running. I may try that but will have to spend some time removing tape, tape residue and silicone grease.

Could this involve the impeller? Are my videos consistent with a problem there?

FWIW will, the pump is a two-speed, 2.0 - .33 hp. The testing/pictures/video show it running at high speed. The filter pressure is holding at about 40 lbs. In the 6 or 7 years I've operated this pool, it has never been 100% bubble free. I have always had a few bubbles and there has always been some air beneath the strainer pot lid and in the salt cell. Finally I'll mention again what I mentioned at the top of this post, that when I first started up the system, there was little air and few bubbles, but only after running a little while did the air infiltration get worse.

I'm pretty much pulling my hair out at this point. It's tempting to begin replacing all or portions of the copper pipe with PVC and hope for a cure, but I would really like to find the leak first. The kids leave for camp tomorrow so I have some time to mess with it. I would be very grateful for any thoughts or suggestions. Thanks.

[I've uploaded additional videos in post #7 below]
 
What I'm hearing sounds like cavitation, but you say the psi is 40lbs. which is exceedingly high and complete opposite of a suction problem. Is that the pressure the filter has always run?

Thanks for responding.

Yes, 40 lbs is pretty typical for the pressure for this system. I usually backwash when it hits 50 lbs. That said, I have no idea if this is a good practice or, for that matter, whether the gauge is accurate.

- - - Updated - - -

I just went thru similar air in basket. Mine finally filled up when I opened all the valves wide open between the pool and pump. Baffles me, but it somehow solved the problem.

Thanks for responding. Yours was one of the threads I looked at while researching my problem. Both of my valves are full open. They are the two PVC ball valves at bottom left in the photo.
 
Nevermind that pressure reading. After looking around at some posts and realizing that 40 lbs is off the charts for most systems, I went out and flipped off the pump. The gauge only dropped from 42 lbs to 38 lbs. It's the original Hayward gauge that came with the filter and multiport valve I bought in 2011. I'll be replacing that shortly.

As to the comment that the pump may be making a cavitation sound, I don't think I would know that sound if I heard it, but I have always thought that pump is louder than it should be.
 
Thanks for responding Mike1162.

On low speed it appears there may be fewer bubbles, but the amount of air in the strainer pot does not decrease and the water level drops in the salt cell. Here is video showing the pump and salt cell on high, then switching to low:
2017-06-11 15.17.38.mp4 - Google Drive

Here is the salt cell about five minutes later with the pump still on low. You can see that the water level has dropped from approximately the top of the "Circupool" letters to the bottom of the letters. (Ignore the sounds in this video as the house A/C compressor around the corner had kicked on between these last two videos.)
2017-06-11 15.27.15.mp4 - Google Drive

Usually, on low pump speed, the water level in the salt cell will continue to drop until the red "water fault" indicator light on the module comes on. Right now it seems to be holding at the level shown in the last video. Maybe the silicone grease and tape on the connections has had a small effect.
 
First, I'd look at the threaded pvc connection on the inlet side of your pump strainer pot. You could remove that black tape from that joint, turn on the pump, then trickle water over that joint & see if that helps out with water flow & decrease in bubbles. Instead of trickling water over that joint, you could also use foamy shave cream and look for it being sucked into the joint.

Regards,
E
 
I agree this a suspect connection. However that is not PVC going into the strainer pot, it's copper (or brass?). I have tried both tricking water over that connection as well as shave cream to no avail. I cannot remove and redo that connection without cutting out a section of pipe because it was installed without a union.
 
I agree this a suspect connection. However that is not PVC going into the strainer pot, it's copper (or brass?). I have tried both tricking water over that connection as well as shave cream to no avail. I cannot remove and redo that connection without cutting out a section of pipe because it was installed without a union.

My apologies for not noticing #8 in your original post.:-| So, if closing off each of the intakes (Drain/Skimmer/Spa) one at a time and you notice no change in flow/bubbles, I'm inclined to think it's an air leak in the plumbing run from the 3-way valve & strainer pot. However, you may want to inspect your pump basket for cracks & check your impeller for clogs. Try putting your filter valve in "recirc" and see if that helps out on the flow, too.

Regards,
E
 

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Thank you. I did a lot of the diagnostics above with the filter in recirculate mode, thinking that I would see any change in the bubbling in the salt cell more immediately that way. The impeller is not something I've checked, so I will go check that out and report back after the pump area is in the shade. (It's 94 degrees in St. Louis today.)
 
Success! Thank you, Satpoolman!

I first tried using a length of coat-hanger to feel for and dislodge any debris from the impeller. I dislodged a small amount of plant debris but didn't think I was clearing it, so I removed the band clamp and impeller cover to expose the impeller. I could initially see that maybe 2 or 3 of the 8 or so (?) channels were clogged, so I wasn't sure that this was the problem. I cleared them with a coat-hanger wire and then shot water from the hose through all the channels to make sure they were clear. Upon restarting, I have zero air in the strainer pot or salt cell! I have never had that condition before, so I suppose that either I have had a partially clogged impeller for several years or in my efforts to find a leak, I tightened up the suction portion of the system enough to reduce the air coming in a its lowest level since I've had the pool.

Anyway, many thanks to Satpoolman and others who responded for helping solve the problem and saving me the money and humiliation of calling a pool guy.
 
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