Our toilet makes a sound after it has filled. This is at a beach house and the water is turned off when no one is there. Last weekend it sounded like someone was outside with a weed-eater (high pitched hum). Ran water in tub, sink, and flushed. Seemed to help but then sound came back. Any one else ever have this problem or have any ideas? Thanks GL
It may be possible to clean the fill valve. Some models have a removable cap with the water to the toilet turned off remove the cap. then put a cup or jar over the valve and turn the water on water rocks & rust scale will usually flush out with a cycle of the float fully opening. Then turn off the water and replace the cap. If your cap is not removable replacement is the next option.
It sounds like (pun intended) your fill valve isn't completely closing, and the water squeezing through is causing the valve surfaces to oscillate (like blowing through compressed lips into a trumpet mouthpiece). To test, take off the tank cover and push down on the float; you'll probably hear the sound change or disappear as you push down, and return as you release it.
The fix is clear: replace the fill valve.