Diagnosing dishwasher wash quality

[paulg]

I would like to hear your tips and tricks for diagnosing a dishwasher that just doesn't get dishes clean like it used to.
In this case we have an eight year old Kitchenaid. For cleaning, a decent performer. Lately it seems that items on the upper rack do not seem so clean. Other items seem ok. Performance is subtly on the poorer side.
The arms are not stuck. Water is hot as I run the water in the adjacent sink to ensure it is hot. We use Finish gel or tablets.
How would one know of the arms are turning properly at all? Suppose the water to the arms is blocked? How do you diagnose?
No fault codes so the machine thinks it is happy I guess.
All ideas welcome!

 

[mrb627]

Water Level

First, be sure the machine is getting enough water.

Malcolm

 

[whirlcool]

It could be a stuck float. This happens sometimes. How far up the tub does the water level go when washing?
It could also be something clogging the filter or the pump too. Maybe pieces from a broken glass?

 

[logixx]

Maybe take a picture of the water level once the tub has filled and post it here.

 

[rockland1]

Poor Cleaning

If your model has a macerator (blade to chop up waste) on you may want to make sure the screen on that blade is not clogged. This happened to me on an earlier model a number of times. It requires taking apart the pump under the wash arm. If it is, the pump can't get enough water to the top wash arm to turn and the top
rack will not get clean. Hope this helps. It's the reason I went to a new model with the filter I clean.

 

[retropia]

Make sure there isn't any obvious problem with the water route to the upper wash arm.

We had a problem with our former Kenmore Ultrawash, where the rubber tube that ran underneath the top rack, connecting to the water supply on the back wall of the dishwasher, was rotted away.

But it was only rotten on the bottom edge of the tube, so I didn't notice it until one day I happened to be on the floor, looking up inside the dishwasher when the door was open. It wasn't visible from above, looking down into the dishwasher.

It was an easy and cheap fix, and then the top arm was getting its full water supply once again.

 

[paulg]

Great ideas all

Thanks so much. All these ideas are great.
This jump-starts my repair project. I'll keep you posted with the results.

 

[mitch]

Cleaning

My mother has a tall tub KA (8-11 years old?) that was not cleaning well. I took it apart and cleaned the sump area out. There are several Youtube videos that show how to do this. Once I got down into the area of the impeller it was disgusting at the nastiness in there! She had a twist-tie from a loaf of bread as well as a couple of toothpicks that was not allowing the nasty water to drain properly. They were jamming up the works basically. I also had to replace the water diffuser in the top of the unit--I am sure she slammed in something too tall and obliterated the spinner . After showing her KA some love it behaved like a new one.

Good luck,

Mitch

 

[mich]

Possibly this...

I've noticed on Kenmore Designed, Ultra Wash machines, theirs a cover in the back of the machine, with a line running from the bottom of the machine to the top. Basically, the line takes your water, from the tub, and is pushed by a motor to give the top rack water spray...

Unfortunately, this design is flawed imo. In my experience, the covers that chooses which level the rack is on, can simply can get worn, and almost permanently pushed in causing water to simply not ever reach the rack

My fix, has seem to be, using plain tape, to keep the bottom hole shut closed. And Pushing the cover (that has the hole on it) back into place, this does a good job, and has held up for over a year now. Of Course, you'll lose your adjustable rack system, completely.

 

[paulg]

Thanks again!

Great tips. Haven't gotten to the task of checking the dishwasher quite yet but you've totally given me a bunch of great ideas.
Will keep you posted on the results!