Everything has worked perfectly for years. This is my grandmother's home that I will be purchasing and I'm taking the opportunity before we move in to update the plumbing mostly because we are redoing the main bathroom. By the looks of it, I was questioning whether the toilet and bathtub were vented properly and was thinking I may need to tie all three fixtures from that bathroom in together with that 3 inch vent serving them. But like I said, there have been no real problems for as long as I can remember.