Air in filter

[JPMorgan]

I am getting air in my filter and not sure where it's coming from. It is a fairly small amount. Usually clears when I open the bleeder valve in about 5-10 seconds. Then, I close the bleeder valve and air starts building up in the filter again. I do also have a little air in the pump lid, but the filter seems worse. What is the most likely culprit... air leak in suction line... o-ring on the filter lid (I've ordered a new one)... issue with multi-port valve... other issues?

 

[Texas Splash]

What is the most likely culprit... air leak in suction line...

The suction line would be my first area of concern. Any leaks past the pump would result in a water leak. The only exception to that is if a leak is so small that when the pump is off, air can get pulled-in to the pressure side as well. Then you might hear water gurgling and moving around in the system when the pump is turned off and air enters. But it's not uncommon to have a little air in the filter. As long as you can bleed it out from the air relief valve and it's not so much that you lose prime in the pump basket, it's probably okay.

 

[Rocket J Squirrel]

I had this problem a while back and the fix was improbable but very simple. I had an invisible crack in the clear pump lid. The crack was so small that water didn't leak out, but air got sucked in. Replacing the lid fixed it for me.

 

[JPMorgan]

Thanks for the feedback. Rocket Squirrel, How did you notice the crack in the pump lid if it was "invisible"? I have looked at that lid very carefully and don't see any cracks. A while ago I did try running water over various suction line connections and the pump itself (to see if I could determine where the leak might be coming from) and (for a while) the air in the pump and filter disappeared. Everything was "air free" for a day or two and then I started noticing air in the pump and filter again. I'll give that lid one more look. I have already cleaned and lubricated the drain plugs in the pump, put a new o-ring in the pump lid, and lubricated one of the o-rings on a connection in the suction line. Today I took apart the multi-function valve on my sand filter, cleaned and lubed that up, as well. The handle turns easier now, but I still have air in the pump and filter. The one thing I haven't touch (because I can't get it loose) is the ball valve in the suction line. That is 20 years old and I wonder if the issue could be there. Should I just change out everything coming into the pump from the suction line at this point (see photo below). None of those connections and valves have been changed in quite some time.

 

[Rocket J Squirrel]

Rocket Squirrel, How did you notice the crack in the pump lid if it was "invisible"? I have looked at that lid very carefully and don't see any cracks.

I didn't notice the invisible crack. I simply figured replacing the lid was cheap and easy, and it worked. I have the bad habit of tightening the lid with a gentle tap of the rubber mallet and figured maybe I (or one of my many pool guys when I still used them) wasn't gentle enough.

The one thing I haven't touch (because I can't get it loose) is the ball valve in the suction line. That is 20 years old and I wonder if the issue could be there.

That is not a pretty valve. But you should be able to check it for air suction.

 

[JPMorgan]

What method is best to use to check for air suction?

 

[JPMorgan]

Just tried the soap suds "method" on all those connections and valves on the suction line coming into the pump and don't see any suds being sucked into anything. Then, I tried running a slow stream of water over that section of the line and also on the pump lid. The air in the pump and filter almost disappears when I run the water over the pump lid, so I am going to try replacing the lid and hope that does the trick. I'll re-post once I have my new lid on the pump. Thanks.

 

[JPMorgan]

Installed a new lid on my Pentair pump yesterday and re-lubed the o-ring. I seem to be getting a little less air in the pump and filter now. Not perfect, but better. If it doesn't get any worse, I'll probably leave as is. If it gets worse, I think I may be time to call the pool company to pressure check the suction line and replace some of those valves and connectors on the last 3 feet of the suction line coming into the pump. Thanks for the help.

 

[Texas Splash]

That's odd that the water test over the clear lid worked very well, then you replaced the lid and while better, was still letting some air in. Seems like a trouble spot for sure. Hopefully that's all it is and not something in the line itself. Good work catching that lid problem.

 

[JPMorgan]

Yeah..... hope it's nothing major. Unfortunately, I think I have to call in the pool company to pressure check that suction line at this point.... and will probably have them replace those valves and connectors that sit just in front of the pump.

 

[JPMorgan]

Is it possible that air in the pump has to do with a pump seal? Could the air leak problem be coming from internal pump parts that have failed?