Okay, we put in a new sink. One basin sits higher than the other. I don’t care for the drains...they seem more restricted than the prior sink. That said, if one basin is closed to hold water and the other needs to drain, it does so slowly. The vortex that lets water and air exchange doesn’t form readily if the strainer is in place but set to allow water to drain (screw type goes in the hole where the vortex would form). We’ve found if we loosen the plug/strainer in the other basin, it lets the air “burp” out and the other sink begins to drain more effectively. Is there a way to correct this issue? Perhaps a waterproof tap that lets out air trapped in the drain pipe but not water?
Was the installation done by a registered plumber? If so, call and complain.
If not, call a knowledgeable plumber. I’m not one, but I stayed at a Holiday Inn before COVID struck. Sounds like it might be a siphon break problem. Do both drain lines come together before the siphon break? Is there a long waste run that is almost flat before the siphon break? Could be as simple as needing larger diameter waste line. A drawing of the waste lines might help someone figure it out.
Best I can do. My hourly rates are not high enough to qualify me as a plumber.
Install was in place before sink changed. Old sink had equal depth basins. I don't recall the old sink having this issue, but again, the drain/strainers are different which may be part of the issue. Basically, when one sink is closed because it's full of water, the other one has no practical way for air to exchange out of the drain pipe as water tries to flow down.
The house has its own vent pipe that goes out the roof. The one basin shouldn't be relying on air from the other basin to drain. Think about a single basin sink, where does it get it's air from? The vent pipe that goes out the roof. Possibility it is plugged by birds nest or other obstruction. Did anything get lodged in the drain pipe when the sink was changed?
The house has its own vent pipe that goes out the roof. The one basin shouldn't be relying on air from the other basin to drain. Think about a single basin sink, where does it get it's air from? The vent pipe that goes out the roof. Possibility it is plugged by birds nest or other obstruction. Did anything get lodged in the drain pipe when the sink was changed?
I'd bank on a blocked vent as well.
It's not the house vent. Both sinks drain through a common elbow. So, when one sink is closed, the air in the pipe before the elbow has only the remaining sink through which to vent. The way the drain is designed, if you leave the screen in place, it has damn little space for water/air to exchange. Burping (opening the other sink to let the air pressure out) gets it working again. To me, it's a sucky design for a sink drain.
it's the screen, my basement vanity does the same thing. drilled the holes in the screen bigger and it works much better. IT has a copper bowl and no overflow hole so I think that causes the same air problem you are explaining.
Our last remodel mandated vent holes in the bathroom sinks. I had learned from a project Mom did where the basins didn't have vent holes in the bowl (design). Slow slow slow draining.
It's not the house vent. Both sinks drain through a common elbow. So, when one sink is closed, the air in the pipe before the elbow has only the remaining sink through which to vent. The way the drain is designed, if you leave the screen in place, it has damn little space for water/air to exchange. Burping (opening the other sink to let the air pressure out) gets it working again. To me, it's a sucky design for a sink drain.
Yep, same thing here. It's a sucky design.