[mickmick]

We have had a new kitchen installed a couple of months ago. The sink is now in a different location to the old kitchen. Next to our new sink is a slimline dishwasher.

We are in the (perhaps bad) habit of chucking our used coffee grounds down the sink. But our sink is not blocked and water runs down the plug at a perfectly quick rate.

Now for the problem. Our dishwasher has never produced good results. At first we assumed that we'd just made some mistake and packed it badly, or prevented the propellers turning or put in cheap tablets etc.. etc.. but after much experimentation, reading the manual etc, the washing is still dirty... or to be more precise... mostly clean and shiny - but with patches of dirt and coffee grounds... we now suspect there is more coffee grounds left on our dishes than there could ever have been on all the combined cups and plates in the first place! So we are wondering if there is any mechanism, or cock-up, that could cause a transfer of coffee grounds and other waste from our sink to our dishwasher.

Is this possible?

 

[jimn]

I hope you are on a sewer and not a septic tank. Even then, throwing food waste down a drain in excessive quantities fouls sewer treatment plants and costs the operating agency more money. Do your tax bill a favor and put the grounds in the garbage or better yet, they make a great addition to a compost pile .

 

[ZZZZZ]

Is this possible?

I'd say nearly impossible, unless the plumbing is totally messed up.

First thing I would look at is does the dishwasher have a filter, and is it plugged up (with coffee grinds)?

Do you have a one bowl or two bowl sink?

Is the dishwasher discharge hooked up through a garbage disposal?

A photo of under your sink would help.

 

[mickmick]

pics

The sink has one bowl. There is no waste disposal unit. The dishwasher filter does not appear clogged. Here are a couple of photos.

 

[mickmick]

I don't know if this is relevant, but I forgot to mention that when we run the tap first thing each morning, it normally splutters a few times, like there are bubbles in the system. Someone told me this indicated that the water somehow rose and then fell again on its route to the tap and gas would build up at the high point.

 

[rjniles]

Several problems

You have a non compliant S trap. But not part of your problem.

DW drain hose routing. Hose should be routed high up in the cabinet not up from the floor. This could cause stuff to flow back to the DW.

 

[Colbyt]

Dishwashers need an air gap or at a minimum a high loop in the hose. The air gap is code most places.