The dishwasher drain should go into the black tube sticking out from the disposal. When you move the dishwasher drain line o the proper location on the disposal, make sure you knock out the plug in the disposal. If you don't, the dishwasher won't drain. Also, replace the pipe that they connected the dishwasher drain to or you will spew junk everywhere when you use the disposal.

Thanks so much for the response.

Could this be the reason for the stench? I told hubby the smell from all the stuff that is supposed to go into the disposal is likely backing up into the dishwasher? And what issues might we run into if we don't address this? His response was pretty much "I'm sure he had a reason for doing it that way." But then the plumber is an acquaintance of his so.....I need to back my complaint to hubby with some solid reasoning.

I think that it is safe to assume that your new Bosch DW has a screen that needs regular cleaning rather than an old-fashioned grinder. Some people don't know about that feature.

When I had that issue I installed an air gap in the sink which solved the problem. It will give you the look and functionality of Jake The Wonderdog's diagram. First the plumber would use a hammer and screw driver to tap out the cap (or plug) that is inside the black tube sticking out from the garbage disposal. Then the plumber would run a hose from the black tube on the garbage disposal up to the air gap which would be mounted on the sink. Then he would connect the dishwasher drain hose to the other side of the air gap. The air gap will prevent any chopped up food from the garbage disposal from draining back (back flowing) into your dishwasher. The air gap prevents a direct connection between the garbage disposal and the dishwasher drain. In some states like California air gaps are mandatory for health reasons.

It looks like you have a stainless steel sink. You might need to make a hole in the sink so the air gap can fit into it. Here's how to make the perfect sized hole. First decide where you want to locate the air gap on the sink and mark the location. Then use a #1 Step Drill Bit to drive a pilot hole into the sink where you want the air gap located. Then there is a metal punch tool that Ikea sells that will cut a perfect sized, round hole for the air gap to go into the stainless steel sink. There is a bolt that connects the top half of the metal punch to the bottom half. Run the bolt through the pilot hole and connect the top half of the punch to the bottom half. Tighten the punch with a wrench until it cuts a perfect round hole in the sink. Here's a link to the YouTube video that shows how the hole punch tool works and the video also gives you the name of the tool = Ikea FIXA 2 piece tool set. If you go to the Ikea store to buy the tool then take the Article Number 285.121.00 so they can help you find it at the store. After the plumber cuts the hole in the sink then have him file down or sand down any sharp edges on the new hole. Once you have the right tools it's a quick fix. It only takes about an hour to cut the hole in the sink, install the air gap, pop out the drain plug in the garbage disposal and connect the hoses.

The few times I replaced the disposal the knock out plugs were plastic, not metal. But still removed before use. My son replaced a disposal once and mentioned that his dishwasher now wouldn't drain. I asked if he removed the plug. His response was DOH.

Ionized_gw,

Are you referring to the filter? I clean that every few weeks. I also wipe all food from items prior to putting in the dishwasher.

oneandonlybobjones,

Thanks for the detailed info. That sounds like a little more than dh might want to venture. Duly noted for future reference in case we need it.

Jake the Wonderdog,

Thank you for the detailed into and the drawings. I showed your post to hubby and he said he'll change it then. :) It's a Badger disposal and it has a plastic plug which is still intact.

Just another thanks to all who responded. Everyone is so helpful here.

Glad to hear that you know enough to clean the screen. Some people, believe it or not, don't.

lorraineg570,

I used to have my dishwasher drain set up like the diagram Jake provided with a high loop but then the high loop fell down and my disposal back flowed food particles into my dishwasher. That's when I decided I needed a "once and for all" solution and installed an air gap. Based on what you said I figured my suggestion would be too much for your DH but I thought you might want to pay a plumber or handyman to make the repair. I also figured someone else would have the same problem in the future and would want to go with an air gap so that's why I provided detailed instructions. Good luck with the high loop! :-)

Lorraine, are you sure those pipes were installed by a master, licensed plumber? I am not one, but it looks like an awful setup to me. I would have the pipes set up so that there is 1 trap for the sink, one trap for the disposal, the dishwasher drains into the disposal's port (with the plug out!) and then the two traps merge behind the wall where the drain pipe goes down and the vent pipe upwards. It just looks like an unprofessional installation to me. You probably don't need one of those drain gap things either if whoever installed all that was more professional.

Neptune Power Washing,

Thanks for the input. I do know that he's been a plumber for 30+ years. My husband is a concrete contractor and he is a business acquaintance.