We have a 5 year old Hayward VL40T32 13” 30GPM sand filter, stored in our shed and not used for the past 2 years, which we now need to use. After rinsing it out and pouring in the sand (w/ water inside and sand cover in place), I placed the multiport valve on top and it wouldn’t seat all the way down flush with the top of the sand reservoir. The gap left was small enough that I could still place the collar, so I assumed/hoped that tightening the collar bolts would pull it down into place for a good seal. I got the bolts as tight as I could, and though they didn’t seem to pull the collar halves as closely together as I thought they used to, I decided to give it a shot and turned it on, but of course it hadn’t sealed properly and leaked.
When I tried to lift off the multiport valve to seat it better the PVC center pipe that inserts into the bottom was in there more tightly than I remember it being in the past, and must’ve lifted the attached inner assembly enough to allow some sand under it, because now there’s an even larger gap when I try to seat the top back on, too large for the collar to contain. Shouldn’t the valve have lifted off pretty easily withought dislodging the stand pipe and under drain, or am I misremembering?
I’m about to remove the now saturated sand and start again, but I’m worried that I’ll end up with the same results. The stand pipe/under drain assembly was definitely seated well the first time, with no sand underneath, but I couldn’t push the valve down on top sufficiently to get it in place for a proper seal. I don’t recall that being difficult in the past. Could 2 years of non-use sitting in a shed have somehow caused the pipe to swell or the valve opening to shrink so they don’t fit together properly anymore? Or did I just screw up my initial assembly, maybe not tightening the bolts enough or something?
When I tried to lift off the multiport valve to seat it better the PVC center pipe that inserts into the bottom was in there more tightly than I remember it being in the past, and must’ve lifted the attached inner assembly enough to allow some sand under it, because now there’s an even larger gap when I try to seat the top back on, too large for the collar to contain. Shouldn’t the valve have lifted off pretty easily withought dislodging the stand pipe and under drain, or am I misremembering?
I’m about to remove the now saturated sand and start again, but I’m worried that I’ll end up with the same results. The stand pipe/under drain assembly was definitely seated well the first time, with no sand underneath, but I couldn’t push the valve down on top sufficiently to get it in place for a proper seal. I don’t recall that being difficult in the past. Could 2 years of non-use sitting in a shed have somehow caused the pipe to swell or the valve opening to shrink so they don’t fit together properly anymore? Or did I just screw up my initial assembly, maybe not tightening the bolts enough or something?
Unfortunately the only remedy is to empty it out and start over. On the next attempt, you might try coating the top of the center standpipe (or female side of the MPV) with a film of pool lube or even liquid dish soap to help lube it. Maybe only fill the filter with enough sand to cover the laterals then test the MPV to see if it seats better with the lube before filling it up completely with sand. At least that way if it still doesn't work you don't have to empty 300 lbs or more of sand.
