Equipment has only been running about 18 months, full Pentair as well, just yesterday water started leaking out the top of the valve. Figure I'll call the pool company tomorrow and see what they are willing to do. Don't know if they'll replace or rebuild. I don't know that I want it cut out of all of the plumbing, but if they are only going to rebuild I could probably do as good a job myself.
I have back washed probably 8 to 10 times. The pressure gauge doesn't go up as much as some note that it should before backwashing, but I can tell water flow is way down by my how much water I get coming out of the spa waterfall. With a Live Oak tree over part of the pool and the amount of stuff I get in the pool I figure it really needs the back-washing, but I could still be over doing it.
Have they replaced your valve or rebuilt it?