View Single Post
Old 08-03-2011, 08:04 AM   #3726
glatt
 
Join Date: Jul 2003
Location: Arlington, VA
Posts: 27,717
Yeah, if you don't have vents, then you get a vacuum effect that will keep the water from draining well. So every fixture is connected to a vent pipe. Sometimes they can get blocked up above if an animal puts something in them.

Like the green pipes in this picture.
Attached Images
 
glatt is offline   Reply With Quote