The island sink has a loop vent under the sink. I installed an AAV and that didn't help. I snaked the drain from under the sink as well as from the cleanout under the house. The laundry tray and washer which are hooked to the same drain under the house drain fine. I'm stumped, I have been plumbing for 45 years and can't figure this out. HELP!

Hi Hcindy

Did you snake down both the drain and the vent of the island sink drain? I'd start there... you'd amazed at how many homes used the vent as the drain in these cases! Post back...

Mark

Thanks Mark, but I added an AAV vent and it didn't help.
Hi Hcindy

Did you snake down both the drain and the vent of the island sink drain? I'd start there... you'd amazed at how many homes used the vent as the drain in these cases! Post back...

Mark

Thanks but I added an AAV vent and it didn't help.
Thanks Mark, but I added an AAV vent and it didn't help.

Cindy,
Try removing the AAV and see if the sink drains with an open vent...

AAV is not necessary since you have "Loop Vent". Also, make sure the sink drain is connected to the DRAIN side of the loop vent - not to the VENT side.

If connected correctly - than check the drain pipe for proper slope

Back to you

Milo