New (and Old) Dishwasher Overflowing

Hello! First off, thank you to anyone who replies. I’m going nuts.

Our old dishwasher started sudding out the bottom, and we decided that rather than fixing a 20 year old machine, we’d just buy another. Now, we’ve got the BRAND new one installed, and IT’S sudsing out the bottom!

I’ve disconnected and cleaned out the hose leading to the garbage disposal, so I know that isn’t clogged, and all of the other hoses are brand new. The sink drains fine. It is normal that the water output of the dishwasher is lower and the input of the garbage disposal is higher, vertically-speaking, right? I can’t figure out what could possibly be giving us the exact same problem, when everything is brand new! HELP!

Yes the dishwasher drain is supposed to be lower than the hose drain.
Here s a good install sheet showing how it should be.
http://products.geappliances.com/MarketingObjectRetrieval/Dispatcher?RequestType=PDF&Name=31-30515.pdf

Is “sudding” mean too much suds?
If yes then it may just be your detergent.
If extreme it could be that the rinse aid has been filled with dish soap.
It does not take much dish soap to cause huge problems.

Add a cup or two of vinegar to the unit before the first fill and then after each refill/rinse cycle. Do not add any detergent.
Do this till there is minimal amount of suds.

If you have changed detergent (brand or type) in the recent past go back to your original detergent.

In spite of the advertising the old style granulated detergent still does the best job.

oh…my. god. I just talked to my wife, and she just “switched” to a new soap right before it happened. This soap was hand-dishwashing detergent! So, we spent $700+ on a new dishwasher and installation, etc because my wife doesn’t know the difference. ::facepalm::

Thanks so much for your diagnosis… how you could figure out what total idiots we are via the internet is beyond me…