A few days ago, one of the toilets in the house developed a noisy refill. It refills normally for a few minutes, and then it gets noisy like there's air in the supply line.
I've observed the inside of the tank during refill, and for the first few (normal) minutes, water comes in through the fill valve and refills the tank normally, and there's a good flow of water from the little refill hose into the tall white tube.
Then the high-pitched hissing noise enters the mix, and flow from the rubber hose slows or stops. I start to see tiny bubbles coming from the bottom of the fill valve, and water starts leaking out of the top of the valve.
Sometimes water shutoff is noisy, and one night we had actually hammering. Most of the time, though, shutoff is fairly normal.
Any ideas?
Thanks!