Main drain plumbing

[run53]

I am helping my father in-law with leak detection. He says he's losing about 2-3 inches per night. In order to help him troubleshoot, I need to understand his plumbing. His pool has 1 return, 1 skimmer and one main drain. there is only a single line heading back to the filter (suction side) so I assume that the main drain is plumbed with the skimmer. Inside the skimmer there is a cover that can slide over the opening to the line going back to the pump. I assume this is used to control the amount of suction from the skimmer versus the main drain if it is partially There is also what looks to be like a valve on this assembly. It's like a plumbing ball valve perhaps. I assume this valve ****s off or turns on the main drain but I'm not sure.

If what I assume is true, I should be able to isolate the main drain, the skimmer and the single return to see if water drops when plugged.

My pool has separate lines for each skimmer and the main drain, so I've never seen this before. I'm looking to see if anyone can confirm this plumbing setup.

 

[JasonK]

I bought an endoscope off ebay for around 20 bucks to run down my lines. I worked like a champ. I have a friend at work, she has borrowed it to do the same. She suspects the main drain line is broken. I'd suggest buying one of them. I bought the 15' model, she ended up buying a 45' model since mine did not make it to her broken line.

 

[JasonLion]

The idea of that float valve is to draw water from the main drain only when the skimmer is blocked (presumably by leaves).

Isolating the main drain requires plugging the pipe at both ends. The end inside the skimmer is easy, but the main drain end is a bit of diving work.

 

[zea3]

Does your father in law have a vinyl or plaster pool? Have you eliminated all other possible leak locations as the source of the leak?

 

[run53]

Does your father in law have a vinyl or plaster pool? Have you eliminated all other possible leak locations as the source of the leak?

It's vinyl with plastic stairs and i already found one leak on the top stair. It was definitely cracked and leaking so I patched it with underwater epoxy. Still waiting to hear the results. However i suspect another leak somewhere because he said even with the crack, the water level dropped below the level of the top step where the crack was repaired. The step crack was quite large so i am hoping I solved a majority of the problem.

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The idea of that float valve is to draw water from the main drain only when the skimmer is blocked (presumably by leaves).

Isolating the main drain requires plugging the pipe at both ends. The end inside the skimmer is easy, but the main drain end is a bit of diving work.

good point. Even if I decided to dive, how could I block that end? Is there a valve or something down there?

 

[zea3]

You would need to remove the cover and put a plug or gizmo in the pipe.

 

[run53]

You would need to remove the cover and put a plug or gizmo in the pipe.

Ya.....not sure I have the right gear to stay under water that long.