excessive air in pump

[Mama Kass]

This is my first post on this site so I hope I provide the info you need to answer my question. I really appreciate all the unbiased help available here.

This is the first year we have had this problem. We have a 6000 gallon above ground, vinyl pool, a 1hp Sta-Rite Cristal Flo pump, and a single polypropylene solar panel installed (for the second year) between the filter and the return. The pressure gauge shows 17-20psi and returns to 0 when the pump is off. Since opening the pool this year there has been air in the top of the filter basket pot, air bubbles coming from the return, and gurgling sounds in the solar collector system. The vacuum is the type that is simply inserted in the supply hole in the bottom of the skimmer. When I try to vacuum, the hose remains floating and the pump gradually takes in more air then loses prime. There is enough pressure from the return that I can barely hold my hand against it (I admit I'm no Charles Atlas). So much for the symptoms.

I have checked the following for wear, debris, and leaks:
1. the large o ring around the top of the basket pot
2. the o ring at the drain plug
3. the threaded connector where the supply line attaches to the pump; I re-wrapped it in Teflon tape
4. the connector and o ring at the wall of the pool
5. visually inspected the 6' flexible supply hose for clogs or cracks; it is only 1 year old
6. saw no signs of leakage under the pump which might indicate a worn mechanical seal in the pump
7. I could not insert my fingers from the basket pot to feel for a clog in the impeller because there seemed to be a cone-shaped "shield" inside the hole.

It would seem my next step is to open up the pump to visually inspect the impeller, but before I tackle that I wanted to clarify whether or not the solar collector system might be the problem. The installation instructions say, "Always fill the system from the bottom" which I took to mean "hook up the supply hose first." I think this is what I did, but it was a very hot, brain-dead day and I'm not sure. Could this be the cause of my problem or is there something else I need to check?

 

[linen]

Welcome to tfp, Mama Kass

Nothing you mentioned suggests to me you have a blockage in your impeller. Everything you have described suggests a supply side leak, made worse when you add the vacuum. You have checked many things...have you relubed the pump basket lid?

One way to find suction side leaks is to run a hose over each connection/seal and see if the bubbles lessen. Wrapping joints in a wet towel can also lessen a leak. Some people use shaving cream to check their joints.

 

[Mama Kass]

Thanks, I'll try that today. I'm glad to hear I don't have to mess with the solar system connections.

 

[btolley]

You have a suction side leak somewhere. I have had this too and it was always something simple. The easiest things to check are:
1) is there enough water in the pool? top it off to be sure
2) does your skimmer weir door work properly? if its stuck you could have this problem
3) remove the pump skimmer lid, lubricate, fill the pump with water and carefully replace the lid
Hope one of those turns out to be your problem.

 

[Mama Kass]

I had done 1 and 3 and the small pool system we have doesn't have a weir door on the skimmer. However when I went to the pool this afternoon to try Linen's wet rag/hose suggestion, I saw water dripping from the threaded connection that I had wrapped with Teflon tape in #3 above. I tightened this connection down and Voila!, no more air bubbles. I must have fixed the original problem by lubing and replacing the various o rings and then created another by not screwing the connection in tightly enough.

When you brought up the subject of the weir door, I remembered an incident from 45 years ago. My pet hamster escaped and we found him balanced bravely of the top of the weir door in our skimmer. Mr. Little lived happily ever after.

 

[linen]

Glad you found the problem ...your experience supports the adage "the last thing you did should be the first thing you check".