Main drain not airlocking

[TyTyTy]

Hi,
I have Pentair three way diverter valves which are new... Pool built end of this year.

I am really struggling to get an airlock on my main drain. Once I blow air with my shop vac, I hear a very slow leak/hissing sound as soon as I close the main drain valve. I can play with the valve a bit and find a sweet spot for where it stops hissing and seems closed but it is so touchy I really don't trust that it won't open back up. I tried adding some lube around the valve gasket and it seems to have gotten a bit better but still really touchy. Any suggestions?
Thank you.

 

[generessler]

If there's no water leak then there's no crack in the housings, it must be that an internal gate seal is leaking. They don't last forever.

Find the parts lists for your valves and purchase a new diverter rebuild kit. Don't assume the link points to the right one. Real part numbers required. That's also a clone. If you can afford it, OEM Pentaire will be better quality, but ~$80.

It's an easy replacement. Take closeup pictures before you start to be sure it goes to back together correctly. (There are no registers; these valves can be assembled in different orientations to get different behaviors.) Remove the lever. Remove 6 screws. Remove the old gate. Put the new one in with new o-rings. Reverse the screw and lever removal. It's just a bit more trouble if you have actuators.

One caveat: When the gate is out, look for roughness on the surface where the rubber seal sits. Mineral scale or scratches can prevent a perfect seal. If that's the case, careful cleaning or valve replacement will be needed.

 

[1poolman1]

Hi,
I have Pentair three way diverter valves which are new... Pool built end of this year.

I am really struggling to get an airlock on my main drain. Once I blow air with my shop vac, I hear a very slow leak/hissing sound as soon as I close the main drain valve. I can play with the valve a bit and find a sweet spot for where it stops hissing and seems closed but it is so touchy I really don't trust that it won't open back up. I tried adding some lube around the valve gasket and it seems to have gotten a bit better but still really touchy. Any suggestions?
Thank you.

Pool valves, while they may do it on occasion, are only designed to seal against water not air. Pure water is about 55 times more viscous than air, pool water even more so.

 

[TyTyTy]

Pool valves, while they may do it on occasion, are only designed to seal against water not air. Pure water is about 55 times more viscous than air, pool water even more so.

Hmm. So what do I do in my case? Just leave it how it is and how it sealed?