I have an automatic pool filler, have had it for years. The original required replacement and I replaced it with a korky. After a short time, when the filler drops and puts water in the pool it makes a clunking sound you hear in the house. I replaced it again, the sound went away for a while, but now it's back. I believe it has something to do with turning the water on and off at the korky. I don't hear anything like that if I turn the water in the house on and off. Any suggestions on what I need to do to fix the problem?