08-08-2022, 07:30 AM
Our MB has dual sinks. There are studor vents at both sinks. The P trap comes into a t in the drain line, the studor vent is about 3" above where the p trap tees in. Both drains then go down under the house and tie in somewhere in the crawlspace, or at least they go down through the bottom of the cabinet. I doubt they are tied in between the base of the cabinet and the floor. I replaced the faucets yesterday. I also replaced the drain in the sinks with a pop-up style. Today while shaving I noticed the drain in the other sink bubbling if I run a lot of water down the drain. I don't think it's ever done this before. The differences are the popup drain and the new faucets can put a lot more water down than the old ones did. So I am wondering if something has always been wrong, but we never noticed because the old faucets didn't put out enough water to fill the drain. I unscrewed the studor from my sink thinking maybe it was a stuck vent, but it made no difference.