Brand new Pentair filter leaking DE back into the pool

[smiticans]

I just installed a brand new Pentair FNS Plus 10008 DE filter 3 days ago and it's leaking DE back into the pool. I have a build up of DE on the opposite ends of the return jets and and a slight coating on the floor of the pool. Yesterday I took the filter apart and cleaned off the grids to look for damage, however, I couldn't find any. I also checked the stand-pipe O-ring and lubricated it with a silicone based lubricant. Everything is brand new (Pump, multi-port Valve, and filter).

I guess my next step is to take apart the filter again and disassemble the manifold and check for any damage. I'm thinking maybe something broke or came loose during shipping.

Am I missing anything?

Thanks

 

[RedScare]

I just spent 5 days looking for the solution to this problem. I replaced my filter grids, which did not need to be replaced, replaced several gaskets, which may or may not have needed to be replaced, and finally I replaced the spider gasket in the multiport valve, which solved the problem. A couple of things to consider. One, do not underestimate the possibility that gaskets are the problem. If you find no tears or cracks, then gaskets are a likely culprit. Second, make sure that you use lube on the gaskets. This is what helps them seat properly and to seal against leaks. Also, turn off the valve leading to your Polaris fitting when adding DE. It limits the path of the DE to the filter only.

Here is my post detailing my DE trials and tribulations. Maybe it gives you some ideas. Good luck!

DE In The Pool - Ugh!!

 

[smiticans]

Thanks for the reply. The multi-port valve is brand new and I don't have any water leaking out of the backwash hose when in filter mode. If I don't find any issues with the manifold, I'll take apart the multi-port valve and check the gasket for any deformities.

I don't have a Polaris either.

 

[smiticans]

I took apart the multi-port valve and the spider gasket appears to be in good shape. I disassembled the filter and removed the filter grids. I took the top manifold off and inspected each individual filter grid. I did not see any holes or weak spots in the seems on the grids. However, each grid had a small coating of DE on the bottom of interior of the grid. I was able to wash that out. I inspected the manifold and I didn't see any cracks on it. The only thing I didn't like was the screen for the internal air relief was easy to remove from the hose attached to the manifold. I also inspected the stand-pipe inside the filter, the o-ring was on it and I did not see any cracks on the pipe.

I put the grid back into the filter and put it into backwash with the lid off. When I turned the pump on, I could see water coming out of the grid where the individual grids attaches to the top manifold.

I called Pentair technical support and they are sending me a new filter grid. Hopefully this fixes the issues otherwise I have no idea why DE is leaking back into the pool.