Hello everyone.. I had to replace my pump and just started up the new one and immediately noticed a definite clicking sound in the valve when in filter of backwash mode only.Did a brief backwash.Sounds like a small pebble or something Do not want to run it as is. please advise. If advice is to remove top of valve please be specific about what to do like drain filter or where to position the valve. filter is 3 yrs old..thanks
filter is DE4820
filter is DE4820