Main drain pool leak

[fstankun]

Hi everyone,

Bought a house 3 years ago and had intermittent leaking since then. For context, Pool is a 16x32' inground vinyl pool and seems pretty old. I'm from Québec, so temperature is pretty cold overnight and my house is on the top of a small Cape. (Sorry not sure that's the right word in english). I'm sometimes loosing 2inches overnight, sometimes 1 inch, sometimes nothing. Last time, leaking stopped after family came at the house and jumped into the pool. Then, leaked started again after robot vacuum cleaned the pool.

After investigating a lot, found out that (kind of?) Hydrostatic relief valve in the main drain (attached) seems to be defective and the o-ring seems bad as well. After diving and making small movements with my hand near it, saw that it sometimes opened without properly closing or even without closing at all. Problem is that I can't seem to find anything like this online. Part number written on it seems to be : Kafko 1003. Main drain body seems to be Kafko 1021.

Is the drain body a one size fit all and I could change it entirely with a newer one with the holes for the main drain + hydrostatic relief fitting on the newer one? (Dream scenario I guess). I think a real hydrostatic relief valve would be better than this old thing. Also, if so, could I change it while there is water in the pool?

Sadly, there is not much pool service around here so that is why I'm at loss for solutions.

Thanks so much.

 

[YippeeSkippy]

Bonjour! Bienvenue chez TFP!
You have a couple of options- repair (possible expensive) or close off that line completely, assuming it is not your only source of drain/circulation?
I can't speak on how repairs are done, especially in your locale, but will refer this to some gurus here who may offer much better advice. @JamesW @ajw22 @mas985
Bonne chance!
Maddie

 

[fstankun]

Bonjour! Bienvenue chez TFP!
You have a couple of options- repair (possible expensive) or close off that line completely, assuming it is not your only source of drain/circulation?
I can't speak on how repairs are done, especially in your locale, but will refer this to some gurus here who may offer much better advice. @JamesW @ajw22 @mas985
Bonne chance!
Maddie

No I also have a skimmer. As you can see on the picture, the main drain is plugged because we initially thought this was the source of the leak, but it seems to be the other "check valve" beside leaking. Never saw another pool with this part yet.

 

[wireform]

I'd say arm yourself with 2 possible sized winter plugs, lift that flap and get the plug in there to stop the water loss then you have time to decide. You say its a vinyl pool and may not need that altogether.

 

[fstankun]

I'd say arm yourself with 2 possible sized winter plugs, lift that flap and get the plug in there to stop the water loss then you have time to decide. You say its a vinyl pool and may not need that altogether.

Just plugged it. Since we have a vinyl liner pool and do not have a high rain season, plus we have a well drained ground, I am also not sure this flap is needed. Thanks !