Suction side leak question


Well-known member
Jun 30, 2008
Suffolk County, NY
Hi guys,

Amazing forum... I have another suction side leak question I am hoping somebody here can give me some help with.

I have a 16' x 32' inground pool. 2 skimmers / returns. Main drain that hasn't worked in 10 years :)
I know for sure I have a suction side leak. Tons of air in the return. Air in the gasket. Pool level drops if I leave the filter off. I actually run the filter 24 x 7 to keep it from losing water.

I have had 3 different pool guys come by and I have gotten nowhere. I have a fairly new paver job around the pool that I would hate to tear up, but I will do what I have to.

The pool guys all pressure checked the lines. 1 said there was a leak, other said there wasn't. :roll: At the time the skimmers were exposed so they supposedly checked the skimmers. There was no leak directly at the skimmer, which leads me to believe it would be in the line somewhere. (If their tests were accurate which I highly doubt)...

My question is, I want to simply know which skimmer is leaking. The plumbing meets underground and comes up together into the pump. I dont have any valves at the pump to turn off. But, is it possible to just plug a skimmer and see if it stops the leak? Cause I tried this. But I do not know if it means anything or not. I plugged one skimmer. Still tons of air. I plugged the other skimmer. Still tons of air.

Should plugging the skimmers one at a time tell me anything? Would this mean there isnt really a leak at those lines?
Or perhaps could it be the main drain? If so, would swimming down there and plugging the main drain help?

I already spent well over a $1,000 on these 3 different companies and I have gotten nowhere. I am adding a spill over spa in the next month and want to have this all resolved before this, because it effects my heater which is another issue. After running for a while the heater starts turning on and off automatically every minute or so. I am pretty sure this is due to the air in the system...

Anyway, any help would be HUGELY appreciated! Thanks a million and sorry for the long winded post.



TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
SWSuburban Chicago, IL

I can't help you, I'm sorry. But I think you have convinced me never to get an inground pool. :shock:

"Waste" seems to be the resident expert on pool equipment. Hopefully he'll be along shortly. Or try a "PM" to Waste.


Well-known member
Jun 30, 2008
Suffolk County, NY
Frustratedpoolmom: I know what you mean. :lol: A couple of times I felt like filling it in with dirt and putting up a volleyball net :)

allyourparts: I would love to, but they are quoting me about $1,500 plus I would have to rip up a lot of the pavers...

My main question is, should isolating each skimmer or main drain by plugging it one at a time, show me which line is leaking? Cause I tried isolating both skimmers already and it still leaked. So should I try plugging the main drain, or is that not a valid test?

If I plug a skimmer and there is a leak in that line, will the system still suck air through that line?

Thanks again!!!

all your parts

LifeTime Supporter
Feb 26, 2008
there are a handful of companies that use a camera to go through the pipes to find your leak
how about trying them?
im sure that the skimmers are on one line.they are tee together some where, you can rule out the main drain by putting a plug in it (although it is easier to do with a scuba tank) and turning off the valve by the system
another good test to see if its the skimmers would be to turn the system off and put your plugs into the skimmers and see if it still loses water
good luck


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
Start with the simple and most likely things.

Eliminate the O-ring at the top of the pump strainer basket lid. Then eliminate the drain plug found at the bottom of the pump strainer basket.

Next, figure a way to isolate each intake so the pump can ONLY pull from that intake.

If you are then convinced that nothing is leaking, examine ALL the joints (elbows, connectors, etc.) above the ground and insure that they are not leaking.

Lastly, your underground pipes....but thaqt's difficult so do all the easy stuff first.


Mod Squad
TFP Expert
Apr 4, 2007
SW Indiana
If either skimmer is leaking in the plumbing, plugging one won't make any difference. Both lines will be filled with water. I'd plug them both (pump off, off course) and see how that affects things. It will let you isolate it to the skimmer plumbing.

It wouldn't hurt to dig up the elbow where the plumbing turns to come out of the ground at the pump. These are common failure points.