I hope you all have some ideas, because this phantom pool leak issue is driving me completely insane! I've lived here nine years and haven't had any real problems with the pool until this year.

Here's the story: The pool is a rectangular, 16'x36' vinyl-lined in-ground pool (the liner is over concrete? concrete/vermiculite mix?). It was built sometime between 1973-1975. There is no main drain at the bottom of the pool.

Since I opened it this summer, water has been pouring out onto the street from my waste/backwash pipe. Initially, the pool was leaking down to the point of the return and intake ports, so I assumed the leak was coming from there. The return port gasket was bad, and since I had patched the liner in the corner last year, I figured that probably had something to do with it too.

So I bit the bullet and $3500 later, I have a brand spanking new liner. They installed it last week and by Thursday, I had it refilled and ready to go. I thought. Then the city knocked on my door to ask why water was pouring out to the street. By Friday night, the water had dropped down to the return and suction lines. By this morning, it had dropped another 5 inches and is at the bottom of my second step.

The pool guys who installed the liner came out this morning and dye tested around the stairs and the ladders. He couldn't find anything and is completely confused (as am I) as to why it's pouring from the waste/backwash line when the pool water level is now well below any plumbing.

He's coming back with some machine to test the liner for leaks. He doesn't expect to find any.

The concrete patio area around the pool looks fine (no new cracks, no sinking, etc). The grass around that looks fine (no soggy areas, no patches of dead grass, etc.). The pool equipment is housed above ground in a shed about three feet from the pool. The pump runs fine when the water is at skimmer level--there doesn't seem to be any suction loss or bubbles coming from the return line. Of course, it only runs fine for a day, because the water level is dropping so quickly.

Does anyone have ANY ideas? The only think I can think of is an underground plumbing leak, but the water level is too far below any plumbing now for that to make any sense. I suspected a leak around the fiberglass stairs...except that the water is coming out the waste pipe!

I am at a complete loss. I'm a widow with two young kids at home and three kids in college; I just don't have another large chunk of cash to put into fixing it! I was really hoping a new liner would solve the problem! Much to my kids' dismay, I'm considering just filling it in with dirt if this is going to be an expensive fix.

Although I hope someone will write back to say "no worries! This happened to me and it cost me $20 and two hours to fix," I doubt it'll happen. But I'm crossing my fingers!!

Ideas??

Thanks in advance,

Mari

You most likely have a bad spider gasket in your multiport valve. This is a very simple and common repair. Any serviceman with limited experience should have figured this out.

However, I checked the multiport valve when the water level was high enough that I thought some could be leaking out there. But now the waterline is feet below the skimmer and intake and return valves and the pump is off, so there's no water being routed through the lines by the multiport valve on the filter.

However, when the water was at skimmer level and the leak was first noticed, I covered the skimmer faceplate to isolate the water in the skimmer line and see if the leak was coming from there.

It isn't. Today, the skimmer still has water in it.

I'm absolutely confused as to how the water is leaking out the waste line when it's so far below any plumbing!

I am 99.9 % certain that the problem is with the multiport. The multiport valve is the one with the spring loaded handle that has different positions or notches that the handle fits into. The handle is the one you change positions to backwash the filter.

It's dropped more and I have only about 10,000 gallons of water in the pool at this point--there's about 4" in the shallow end. The waste line is now trickling water instead of gushing it...but it's all very illogical. :/

They're coming out tomorrow afternoon to do more leak detection. In the mean time, I'll completely disconnect the waste line from the pump.

I wish I had a schematic drawing of my pool's underground plumbing though.

Note: There are other lights that aren't so easy, but this is the most common. The crew who installed your liner should be able to fix it.

Hope this helps.

If you have a flooded suction, it will drain on a continuous basis but slower when the pump is off.

If the pool is fully plugged and continues to leak and you have a light, the conduit is broken or rotted, or the niche has a hole in it. Sealing it with potting compound or butyl tape should solve it. I assume they used new gaskets when you changed the liner.

If the leak stopped when the pool was plugged, then a pressure test is called for.

It is possible there is more than one leak.

Scott

I was wondering if you ever found a solution to this issue? I am having a similar problem with my vinyl-lined pool where it is losing water still after I closed it. The water level is now below the skimmer and the jets and I'm stumped.

Any insight would be appreciated.

Thanks.

Scott

Thanks for the quick response.
-No light
-There is a main drain in the deep end
-I don't know the exact age of the liner - I would assume it's original to the pool, so it has to be at least 15-20 years old.

I did have a leaking spider gasket during the season, but I replaced that and sealed it up good and tight.

Scott