I've recently installed a single bowl farmhouse kitchen sink, but I'm dealing with persistent slow drainage problems. Despite using a 20-foot sink drain cleaner to ensure there are no blockages in the main pipe, the issue remains. I've tried various configurations, including setups with and without a garbage disposal, different types of P traps, and numerous angles and turns in the piping. With my previous two-bowl sink, I never encountered this issue, likely because it had a different drain orientation that allowed for better water flow. Currently, the drain is located in the center, and it seems like the water pressure runs low as it tries to navigate turns into the wall, which I can't alter because it would mean tearing down the cabinets.
I'm looking for suggestions on how to resolve this. I know I should reinstall the garbage disposal, but when I tried it just now with a simplified configuration, the flow seemed worse due to the shorter path. Is there a garbage disposal that can also work as a pump? Or am I completely off base with my thinking?
2 Answers
It sounds like you've got a few things that might need addressing. First off, a trap is essential for your setup. Secondly, consider adding a vent or an air admittance valve which could really help improve drainage. Lastly, ditch that flex pipe if you have it; rigid pipe is generally better for drainage flows. You mentioned the two-bowl sink had better drainage—was it vented? That could be a key detail. Just out of curiosity, do you have a pic of your plumbing before the remodel?
I agree with PlumbingGuru42 on the vent and the P trap; those are definitely necessary. The air admittance valve could be the game changer for your drainage issue. If you didn’t have vents in the old setup, that might explain your easier flow with the two bowls. As for the garbage disposal, it’s probably still a good idea, but ensure it’s a model that supports good flow and isn't just slowing things down. Consider getting rid of that flex pipe too, it can restrict flow more than you realize! Good luck with your plumbing rebuild!