For this type of valve it is normal for there to be some hissing as the tank is nearly full, because as the float rises with the water level, it is gradually closing the valve. The hissing is the sound of water movement through a nearly-closed valve.Jan 27, 2016

Why is my new fill valve hissing?

A hissing sound can mean that the refill valve is still letting a tiny bit of water into the tank because it hasn’t shut off like it’s designed to. The valve shuts off automatically based on the water level in the tank. A faulty valve or one not set properly will keep running.
May 4, 2020

How do you fix a hissing fill valve?





Quote from the video:
Quote from Youtube video: Shut. The water off to the tank. Remove. The black cap off the fill valve grab the extension arm on the head of the fill valve by giving a quarter turn counterclockwise. Remove any visible debris.

What causes a toilet to make a hissing sound?

A: The hissing noise is most likely a defective refill valve. There are two valves inside the tank on the back of the toilet bowl. One is the flapper valve, located at the bottom of the tank, which allows water to enter the bowl.
Oct 3, 2009

Why do I hear air when I flush the toilet?

A toilet making an air noise or a whistling or hissing sound is a sign that the fill valve is not closing and sealing properly, and air or water is leaking from the fill valve. If the fill valve isn’t closing properly, begin by replacing it. If this doesn’t solve your problem, call a plumbing professional.
Feb 17, 2020