House was built in early 2000's and we bought it last year. Always had this slight knock, but figured it was air in the lines or something. Investigated it today looking for loose pipes, but that wasn't the thing. All the sound is coming from the main water valve in the basement. Any suggestions as to what it might be? Is the valve shot, can I fix it? Do I need to call a plumber?
[video=youtube_share;nY_PAxphcso]https://youtu.be/nY_PAxphcso[/video]
[video=youtube_share;nY_PAxphcso]https://youtu.be/nY_PAxphcso[/video]