[blackrhino]

Dear Plumbers:

I have 2 fairly new Fisher Paikel drawer dishwashers on each side of my sink, they are only about 4 years old and have worked great for all that time, each of them draining through the garbage disposal and into the sink drain. Til recently that is, and I don't know what changed but all of a sudden, the rinse water now drains into the other washer and it happens with both of them.
We took the plumbing apart and there are no blockages, the sink and the disposal drain fine, also I replaced the air gap, though the guy at the hardware store said mine wasn't bad.

Any ideas? The plumber that installed them is long gone. It seems like a simple fix since there aren't many parts to deal with, but nothing seems to have worked.

Thanks in Advance.

Deb

https://www.askmehelpdesk.com/images...s/confused.gif

[doug238]

Maybe you need an airgap for each unit

[p22101]

How are the two dishwasher connect where they empty into the disposal?

Doug

[doug238]

Just guessing here, but if you got 2 dishwashers and an airgap is being used and water is backflowing into the other dishwasher then I am also guessing the both dishwashers may be connected before the airgap.

[speedball1]

I think Doug nailed it. You have two drains that are joined into one line leading to a air gap and then into a disposal unit. A recipe for disaster if you have any back pressure at all. If you didn't install a air gap on each drain then did you at least install a high loop on the drain without a air gap? Regards, Tom