Air in the filter. What does it mean?

Bart

LifeTime Supporter
Jan 25, 2010
285
0
Northern Virginia
#1
Lately I've been noticing air building up in my filter. When I open the little valve on top, I get about 5-10 seconds of air coming out before the water starts flowing. It seems to be about the same amount of air whether I crack the valve once a day or once a week which suggests to me that there's a certain maximum volume of air that builds up in there and once it's reached, no more new air enters.

I don't know if that makes any sense. But like I said, if I check it once a day or once a week, the amount of air coming out seems about the same.

Any idea what's happening here and why? Should I be concerned?

I'm running solar heating which may(?) contribute to air leaks in the system

Thanks!
 

Bart

LifeTime Supporter
Jan 25, 2010
285
0
Northern Virginia
#3
I don't recall seeing any bubbles, but I'll check when I get home.

Not sure about holding prime either. But maybe this is related.......when the pump kicks on in the morning, it runs for 30 seconds to a minute before any pressure is built up or any water starts flowing. When I look down into the strainer basket, I see water way down at the bottom, but the basket is empty.
 

techguy

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TFP Expert
Jul 21, 2010
2,697
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Antelope, CA
#4
If your pump basket is full of air, you are leaking somewhere. As this is an in-ground, I can assume your pump and its basket are above the water level so i would start by adding o-ring lube to the gasket on your pump strainer lid. It may be as simple as the water from your pump is draining back to the pool due to an air leak in the lid. This is most likely source in my mind, assuming you have not damaged any of your suction piping.
 

jblizzle

Mod Squad
LifeTime Supporter
TFP Expert
May 19, 2010
41,193
4
Tucson, AZ
#5
It is possible if you are not seeing air in the pump basket when the pump is up and running, that the leak is up in the filter. When the pump shuts off, the filter leak allow air in which lets the filter and pump drain down.

So, are you sure that the air builds up while the pump is on? Or is it possible that the air enters the system when the pump is off?
 

duraleigh

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In The Industry
Apr 1, 2007
31,263
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Sebring, Florida
tftestkits.net
#6
Any leak on the pressure side of the system with the pump running will result in visible water...pretty easy to find.

It is almost surely a suction side air leak. Why it builds to a point and stops, I'm not entirely sure. My guess is it reaches a point within the filter where it can be blown out through the return so OP should see bubbles coming out of the return after a while.

Anyway, whether it stops or not, the source of the leak can be found somewhere between the skimmer and the pump and it is simply gonna' take detective work to ferret it out. Always start with the O-ring being seated properly and in good shape.....that's the most common spot.

(your solar is on the pressure side....that's not it)
 

techguy

LifeTime Supporter
TFP Expert
Jul 21, 2010
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Antelope, CA
#7
I forgot to mention, I had to replace my pump's lid a couple years ago due an unresolved leak. New lid, new lubed gasket, problem solved.... but my leak was easy to see with the pump basket being below the water level, it was always under pressure and when the pump started, the basket would fill with air and lose prime. AGP pumps are not self priming and require a full basket or they simply pump air, cavitate and get hot (and die).
 

gordyjamz

Active member
Aug 8, 2007
34
0
Illinois
#9
Yeah I would check the o-ring on the cover. They tend to flatten with time. Also, any o-rings on/in the filter itself. Plus any hose clamps that you may have may need to be tightened. Also, a low level of water in the skimmer may cause the pump to suck in some small amounts of air which could build up over time.