After flushing my toilet it makes a loud hissing sound while filling. Everything seems to be working properly except that.

Jeannine, June 2007

this is probobly a reflection of your water pressure - -you may try a "ballofix vale"

this is a small isolating valve fitted to isolate the supply to the toilet-- fit it and try turning it down a touch- obviously the toilet may take a little longer to fill.

A new installation should have isolating valves fitted anyway

dave broadbent, June 2007

the rubber diaphragm inside may of gone hard, replace

hi-spec plumbing, June 2007