My Hayward SwimPro SW166T/164T is blowing sand and debris into the pool during filtration. It has always done it during backwash if I don't shut the valve on the return hose.
The laterals and hub were new last summer. Only had the prob during backwash. Now it's always.
I emptied sand and thoroughly inspected the umbrella laterals, hub, and center pipe. No cracks, no gaps, it still looks brand new. It is seated up top so well, I can't pull it apart.
The only prob I saw was the gray "basket" looking thing that is on the base of the control valve (it's black on new ones) had fallen down and was lying in the sand/water in tank. A repair guy at our pool store said that would have nothing to do with it. I epoxied it back up where it belongs.
So, is there something up in the valve that is bad? I'm stumped.