Toilet Hissing

[William Howe]

Hello all. Ive been having a problem with my toilet and was hoping to get some help. My toilet has been making a constant nonstop hissing noise. I tried tightening the screw on the fill valve holding the float, but ran into another problem. By tightening the screw, I am lowering the waterline. If I lower my waterline the toilets flush is weak and if I raise the waterline back up the toilets hissing noise returns. Any solutions on what I can do?

 

[Twowaxhack]

Replace the ballcock.

 

[TomFOhio]

I like Fluidmaster fill valves