Originally Posted by
amateur plumber
I replaced the flapper and it is still doing it. The name brand on the pump is "HushFlo, anti-siphon". It shows arrows to lower and higher. What is that for? There was a knob on it that could be loosened or tightened and I tried both ways and it still doesn't help. When the toilet first flushes and fills, the water does stop about an inch from the top of the overflow. But then I can sit and watch it raise up to the top of the overflow and start running it. Any suggestions?