We remodeled our kitchen a few years ago, and replaced our double basin sink with a single. The old double sink drained fine. The new one drains slow enough that water will build up with standard flow. I can turn on the disposal, and it drains fine. The depth of the sink changed about 2", but we're not talking about standing water from the wall drain being too high, just drains slow. We changed nothing in the wall, and the difference in drain rate was immediate, and has remained the same ever since the remodel. Please help.

Hi sounds like you have the wrong trap on the waste .Should be white s shape, not bottle type. Or the trap is blocking below the sink it should only be hand tight if fitted right , hope this helps

Jazzas... Where do you come up with that idea? Never mind that the trap shouldn't be S-shaped (these are illegal everywhere), it should be U-shaped or Pshaped, if you will.

The issue here sounds to be an issue related to venting, or it could just be the new rubber seal at the disposal collar. Here, sometimes the rubber seal cuts off the vent contribution to the drain until it passes past the rubber seal and then everything drains fine... ;)

First thing I would suggest is to remove the rubber seal at the disposal drain and run water... see if that improves things! Next, if that failed to show the issue I would start looking at how this sink is vented, if at all!

Back to you, Matticus!

Mark