WHY DOES WATER COME UP INTO THE AIR VALVEON TOP THE SINK WHEN IT CHANGES CYCLES

Hello Paul Maksymowicz & welcome to FIXYA, Your ERROR code SEEMS to indicate you have indeed filled your SAFETY tray (designed to prevent FLOODING). FRIGIDAIRE's solution is to UNINSTALL your unit and (TIP) drain your dishwasher to eliminate your "i30" ALARM condition... Without intervention the SEWAGE situation (I suspect) will reoccur... FIX IT...!! To ELIMINATE the DISPOSER flooding condition (building codes usually require an elevated SYPHON BREAK (adequate))... to prevent back-washing of WASTE-WATER into your cleaning unit (serious health & safety issue). FOLLOW proper installation procedures... (read the manual) and avoid poisoning yourself, your family, associates, visitors, friends & loved ones... (my opinion). https://en.wikipedia.org/wiki/Carnac_the_Magnificent

Check your sink air-gap and disposal hose. Over time those can get clogged with food. Please rate me. Thanks. Have a great day!

Hello Rdmkl, That is actually called the "air-break" or air gap device. It's purpose is to prevent the dishwasher from sucking back any water from th sink trap and/or disposal when the sink is being used, etc.

You should be able to gently remove the cap from this and then clean out the filter element and flush the line with some warm to hot water to clean out any buildup in the line.

Otherwise, everything is working just fine. The reason you're likey seeing the water leaking out of the air break is due to it being gunjked up with debris, so a good cleaning shoud take care of everything.

If after cleaning it you still are getting some water leakage, then you'll want to remove the drain line going from the air break to the sink drain connection and clean the line by flushing it with hot, soapy water until it runs freely.

Hope that you find this Very Helpful and best regards!

Since this just started, I would suggest cleaning out the p-trap under your sink. If your sink drains sluggishly without a pump, then your dishwasher will overflow your drain pipes with its pump.
Also, try facing any air gap opening into the sink.
If the pipes are clear, you may need to add a length of pipe between the air gap on the sink and the 'y' connector that the drain lines are connected to. This will help keep any splashing water from 'climbing' out of the sink-top vent. Good luck

YOU ALSO HAVE A VENT ISSUE, THE VESSEL SINK DOESN'T HAVE THE LITTLE HOLE IN IT LIKE A VANITY SINK, THERE FOR THE WATER IS GOING DOWN THE DRAIN BUT THE AIR CAN NOT COME OUT, YOU NEED TO INSTALL A STUDOR VENT OR AN INLINE VENT INTO THE DRAIN BETWEEN THE WALL AND THE TRAP CUT IN A TEE AND BRING A PIPE UP TO THE BOTTOM OF THE COUNTER TOP AND INSTALL THE VENT, USALLY HAVE TO PUT A FEMALE ADPT ON THE TOP OF THE PIPE THE VENT COMES WITH THREADS DO NOT GLUE IT IN PLACE, THEY HAVE A RUBBER FLAPPER THAT OPENS WHEN THE WATER IS GOING THRU THE DRAIN AND ALLOWS IT TO PULL IN AIR THEN THE FLAP CLOSES WHEN NO WATER IS RUNNING TO KEEP THE SEWER SMELL OUT

Almost all dishwashers connect to the sink drain in one way or another. Many connect (via an Air Gap valve) to a garbage disposal.
If the "metal part" is at the rear of the sink, that is the top of the air gap. When water comes out of it, that means the drain is plugged.
If there is a garbage disposal, does water drain through it? Does the disposal work?
If there is no disposal, does water from the faucet run through the drain of each sink with no problem?
Thanks for answering these questions in a reply.

Possible your filter is clogged, clean out. Your exit hose should not go too deep into the standpipe in wall, and it should not be air tight there. The height of approx 3 feet should be maintained. You can check the exit hose by laying it to floor level to see water flow out freely, or put into sink & try 'spin'.

If things work out, rate.

First off, clean the surface where you select the cycles, over on the right side of the drawer edge. Clean up the entire surface, so that when you lightly touch the cycles, It changes instantly. Also, you said "dd603" but the LP/HP modes are for model 601 and 602.
Open the drawer, select normal first. Now with two hands, hold your fingers over the two outer-most buttons, one on the left side and one on the right. Wait up to six seconds and then the LEDs should all come on in an orange color and the display should show the LP. Press the lock button once, it should change to LP. Make sure you are looking for a manual for a dd601/602. You can get them free at http://www.fisherpaykelparts.net

The drain in to the garbage diposal is clogged.  Remove the drain hose from the dishwasher and clean the hose.  Also check the inlet to the garbage disposer and clena it.

check all your pipes under your sink to the outside grate for blockages, water does come out at some force, the pump would be faulty if it didn't, if its just volume of water, locate the outlet into another pipe further down the drain away from the sink, hope i have helped if so rate me please