Why does my kitchen tap make a whistling noise?
Like air through a whistle, when water goes through a restriction like a partially open valve, it could cause a self-sustaining oscillation that results in a whistling sound. It could also be that the rubber valve seat (washer) has become hardened with age and vibrates to cause the whistling when the valve isn’t open all the way (like a reed in a woodwind instrument). The conditions probably weren’t right for this to occur when the valve was installed. But, hard water deposits might have accumulated just right to form some kind of condition that causes the oscillation, resulting in the whistling. I would recommend removing the valve stem from the valve (turn the water off at the supply valve first), and check the washer and valve seat inside the body for deposits that might cause the problem. Also, check the pliability of the washer. It should be like soft rubber, not hard like plastic. If you suspect a bad washer, take it with you to the plumbing section of a home improvement store an
