When Good Dishwashers Behave Bad

Myself and my dishwasher have not been getting along. It started with presenting dirty dishes after the cycle had ended, leaving a hazy film on glasses and noticeable “dirt” on white plates.

Of course, I wasn’t happy about this. The kitchen appliance that was supposed to be saving me time, was instead creating more work. I had no choice but to hand wash more and more dishes.

I had to take steps to clean my dishwasher (yeah, I know, ironic, isn’t it?). In the process, I learned about the steps  to get my dishwasher back into peak cleaning performance.

There are multiple reasons why your dishwasher may not be cleaning properly. The big one for me: hard water. I go over several reasons why a dishwasher may not do a good job cleaning. If you’re in a hurry, don’t miss the after picture of using CLR in the dishwasher –  I had amazing results!

Standard reasons dishes and glasses come out of dishwasher dirty

The most obvious sign your dishwasher is not operating well, is that the dishes are coming out clean instead of dirty.

Here is a picture of my dishes in question. These are Corelle plates that came out of the dishwasher dirtier than when they were loaded [for real] dirty. The film seems to have “baked” on (I’m thinking in the dry cycle), requiring hand scrubbing to remove. Some users describe this dirt as a stain.

Since I have been using a dishwasher for decades, I knew that this type of “baked on” dirt  or staining was not the normal scenario of the dishes not getting clean – the dishwasher was actually making them dirty. More on that in a moment.

The standard tell-tale signs of dishes not getting clean are  powdered soap still remaining (clumps left, or left inside glasses) and food debris not washed away.

Dishes not cleaned by dishwasher due to dish type

Dishes like bottles with small necks will not clean out well in a dishwasher. It’s just not possible for the jet streams of water to shoot up inside of a bottleneck, tall glass, vase, water bottle, Mason  jars, etc. These items do best when hand washed with a bottle cleaner brush or other long, narrow brush in the kitchen sink.

Squeeze bottles, drink bottles such as Gatorade and Powerade, and sports bottles will not be fully washed inside if using a dishwasher due to small opening in these types of bottles.

UPDATE: I just read my dishwasher manual and there is such a thing as “bottle wash” (on some models of KitchenAid dishwashers, not mine). I didn’t even know that existed!  This is what my manual says: “The upper rack has flip-up spray nozzles that reach into deeper items such as sports bottles, baby bottles, or oddly shaped items. Flip the nozzles up to use them and down to move them out of the way.”

If you are curious, capacity is up to “three sports bottles, baby bottles or other narrow items may be washed in the upper rack with this feature.” If you know someone with this feature, ask them how they like it. It could be a great idea, but not actually work so good. Read more on concerns about washing water drinking bottles and baby bottles in your dishwasher.

Dishes not cleaned due to incorrect stacking of dishes

Pet peeve alert. There’s a right way and a wrong way to stack dishes. Dishwasher racks are designed for dishes to be spaced apart for the water jets to reach every surface. Here are the instances of poor stacking that result in dirty dishes:

  • dishes sandwiched together
  • big dish completely covers smaller dishes underneath it
  • dishes to tall or too big (cookie sheet or cutting board) that block water jet spray or prevent spray arms from freely rotating
  • concave dishes placed facing up, rather than down (such as a bowl, I’ve had this talk with my kids, believe me)
  • concave dishes not facing inward
  • utensil heads facing down in basket

I’ve had several dishwashers over the years. I was excited to get a Bosch dishwasher, because I thought it would run quieter. It seemed to be an improvement, but I ended up hating it. Bosch is German-made (or should I say German-designed). For some reason, my United States dishware did not fit well in the Bosch dishwasher.

I could load dirty dishes into a Maytag or KitchenAid with my eyes closed (and has a mom raising kids, that’s probably how it happened!). I found it frustrating to take extra time to get my dishes to fit, which never fit perfect on the racks. Anyway, just a random insight I wanted to share.

Dishes not cleaned due to dirt challenges

All food should be scraped off the plate before placing in the dishwasher. You may have seen advertisements that say otherwise, but it’s a pretty dumb thing not to do. Dishwashers actually come with their own little garbage disposal at the bottom, otherwise there would be constant issues of food plugging the drain. There is no reason for asking for trouble.

Dried on food will also prove challenging to a dishwasher. If you don’t have a full load, rinse the dishes off in the rinse cycle, or in the kitchen sink. Some people may not understand that dishwashers are not expected to be able to clean dried on food.

Dishes not clean due to plugged dishwasher arms and screens

Dishwashers are a marvel of engineering, designed to get dishes as clean as possible. The increase of water spray patterns is quite impressive.

The holes in these arms suck up the water inside the dishwasher and recycle the water back out. It’s OK, remember, the dishes all gets rinsed at the end with clean water. Those tiny holes in the arms can get tiny flecks of paper stuck in them from jars, little hard stuff like popcorn kernels, and tiny plastic that might be left on a pre-packaged food container.

You may be wondering (like I did) if the little plastic package from laundry detergent pods could also get stuck in the arm blades of the dishwasher. It can’t. According to Kitchenseer, the tablets are covered with a plastic that dissolves in water.

Closeup pictures of cleaning arms, filters, and screens of KitchenAid dishwasher.

Dishwasher manufacturers recommend to clean out dishwasher filters when:

  • Visible objects or soils are on the upper filter assembly.
  • Dishes feel gritty to the touch.

In addition to cleaning dishwasher filters, I sometimes have to remove debris from the blade assembly holes. If you want to attempt this, inspect each hole carefully (you can see debris stuck in the blade spray hole in the picture).

I take a tweezer and pull out debris from any plugged holes. Sometimes I have to take a toothpick and push in debris if I can’t pull out. This isn’t something that you have to do all the time, but it’s a good idea if you notice a drop in quality when the dishwasher runs a cycle.

Don’t forget to check the screens at the bottom of the dishwasher. The screen in my KitchenAid dishwasher is like an upside down cup. I have to unscrew it, and then wash it out under a sink faucet. There is also a flat, circular screen that removes from the bottom of the dishwasher – that should be rinsed out, too. FYI, don’t use wire brushes or scouring pads on the filters, it could damage them.

Be very careful of sticking your bare hand in the receptacle the cup filter screws into. It usually is filled with water. Sometimes if I have a broken glass, there could be glass shards in there. Use a paper towel or rag to absorb the water sitting at the bottom. That should clear the way for you to see if there is anything lurking in the bottom of the dishwasher.

Use the right dishwasher detergent and rinse aid

Using the right dishwasher detergent does make a difference. I was always told by my local appliance guy that it didn’t matter what dishwasher soap I choose, just use the cheapest powder soap and only use 1 tsp. One day I bought liquid dishwasher detergent because the powder form was out.

The dishes came out surprisingly clean – my friend commented on the same results. Two people does not constitute an official test, but that was our experience.

Just a point to emphasize – dishwasher is specially formulated to work with the dishwasher. It is low foaming. This is an important point – you cannot use regular dish soap like Dawn dish soap in a dishwasher, or you will have bubbles leaking out of the machine. Dish soap won’t hurt the dishwasher, it just won’t clean the dishes properly and will create its own mess to clean up.

In regards to rinse aid, I always thought it was a marketing ploy Rinse aid is touted as important for leaving your dishes sparkly clean (instead of with water spots), especially if you live in areas with hard water. Now that I know how hard my well water is, I always use dishwasher rinse aid.

I have never used dishwasher pods, which are a detergent + rinse aid product. Again, seems like marketing ploy to get more money from me. I do know that many people are anti-pod because they are bad for the environment for several reason.

Use hot water for the first rinse for cleaner dishes

A trick that some people recommend is to run hot water from the faucet in the kitchen sink briefly before starting the dishwasher. The reasoning here is that since the dishwasher and sink are on the same water line, the dishwasher will get the immediate benefit of hot water in the first rinse. I’m not sure, but I think many dishwashers start with a cold rinse to save money.

Don’t let the water softener run out

Ouch! Yes, this happened. You may never have to deal with softener salt, but out here in the country, we do. Our ground water well is known for very hard water. To counteract the affects of hard water, salt pellets must be added to a water softener (hard water leaves residue on skin and hair after showers, lime deposit build up in toilets and water lines, and leads to poor cleaning of laundry and spots and hazy film on dishes).


Dishwasher not cleaning glasses properly, left with a hazy film.

Dishwasher not cleaning glasses properly, left with a hazy film.

The glass in the picture is supposed to be sparkly and shiny. It may be hard to tell because of the amber color, but it has a foggy film. This glass was a victim of hard water that was not properly treated with water softener pellets.

I don’t have any examples of my clear glasses, because I scrubbed them all clean with baking soda and soapy water.

Forgive the vintage drinking glass, it escaped my cleaning wrath – at least I have something of proof to show you!

A bit of a miscommunication between my husband and I left the water softener out of softener salt for too long. This meant that the teeny, tiny holes in the water blades became stuck with line. I asked my local repairman about it, and he said that if there is lime build up in the blade, it will prevent the blade from spinning (the blade became slightly heavier at one end, and it needs centrical force to spin properly when the water rushes through).

The worse case scenario was to replace the blades for $30 per blade, not to mention the labor. The repairman showed me how to twist off two of the blades, but the other ones were connected to a bigger arm, so removing would be a more complex job.

Removing lime and hard water deposits from a dishwasher

Before we tried that, he recommended cleaning my dishwasher with vinegar and/or Tang drink powder mix. I wanted to give that a shot, since the water softener was only out of salt for a few weeks.

I should first preface that I drove to town and picked up more water softener salt to refill the water softener. I couldn’t attempt to clean the dishwasher right away, because the water softener has to go through a few cycles to get fully flushed into the water.

My appliance dealer instructed me to add 1 cup of vinegar to the bottom of the dishwasher after I heard it completing the first rinse cycle. He said to expect several cycles in which I could open up the dishwasher and put vinegar in.

It was nearly impossible to do this. I couldn’t discern between the sound of a wash emptying out and regular wash function. In addition, by wash cycle takes over 2 1/2 hours! I just kept opening up the dishwasher and randomly throwing cups of vinegar in.

I also followed up with Tang. I can vouch that the inside of my dishwasher looks shinier. When I threw the Tang in after about the first 20 minutes of operation, I failed to restart the dishwasher (I hate my dishwasher, the panel is hard to press). I returned to find my dishwasher off and the Tang sitting in the bottom, so I had to restart.

The verdict? Things are better, but not completely. I want to do another cycle of cleaning. I am also a little suspicious if the years-old water softener may not be doing its job properly. UPDATE: I moved on to the CLR cleaner below, see the updates here.

Using CLR (Calcium, Lime, Rust Remover)

I couldn’t write an article about  hard water deposits in dishwashers without mentioning CLR Remover Cleaning Product. If you’re not familiar with the product, it is designed to removed calcium, lime, and rust. It’s pretty much a staple cleaning product for anyone who lives with hard water and rust problems.

Examples for using CLR include rust streaks in toilets, hard water around faucets providing hard drinking water, water spots on showers, etc.

The official CLR website has an article on unplugging a clogged dishwasher. I assume they’re talking about calcium in the dishwasher arms:

To clean your dishwasher, remove the dishwashing rinse agent and pour a 1/2 cup of CLR Calcium, Lime & Rust Remover directly into the bottom of your empty dishwasher. You can leave the racks in the dishwasher, but remove any glasses, dishes or flatware. Run a normal cycle followed by an extra rinse cycle. Make sure there are no detergents or any other chemicals in the dishwasher while using CLR.

So to clarify, CLR can be used in a dishwasher void of dishes, but racks can remain. Bypass the detergent tray and pour a 1/2 cup of CLR directly into the bottom of the dishwasher. Use the regular wash cycle followed by an extra rinse cycle

If you are worried about CLR damaging your dishwasher, I wouldn’t. The fact that the company is promoting it specifically for dishwasher unclogging indicates they have faith in their product.

Just know that my local appliance guy mentioned “they don’t make CLR like they used to – they had to take out the good stuff for environmental reasons.” *Sigh* I do like a powerful cleaner, but I do get that we have to leave a healthier planet for our loved ones. If you have concerns about safety of the product, know that CLR has gone through at least one re-formulation of the product to make it safer to use.

UPDATE: Results of using CLR in dishwasher

Clean dishes after using CLR in dishwasher.


Clean dishes after using CLR in dishwasher.

I used CLR to clean my dishwasher and wow! It’s the cleanest my dishwasher has been in months! They feel clean – this is a big deal! The dishes were feeling gross even after washing. The brown glass did not improve. I will have to hand wash it because the lime build up was too much inside . It’s used as a water drinking glass and hard water is often left sitting in it.

To be completely honest, there were two dishes out of the batch that had debris left on them. I’m a little puzzled by the one dish, I think it is the position sitting in the bottom rack. The other was a pot that probably had dried food in it. I’m pleased to report that even the inside of the coffee cups were sparkly! This is such a huge win. At least a third of my dishes had to be re-washed by hand before, and the rest were questionable. I’m pretty darn happy!

In conclusion

There are actionable steps to take that can get your dishwasher turning out clean dishes again. If none of these things work, you may have to reach out to a repairman.

It is worth mentioning that if nothing seems to remove the cloudiness from glassware, it may be permanently etched. The tiny, micro abrasions can be caused by the wrong type of detergent, too much of it, or water that is too soft. Even cleaning off dishes too much, according to The Spruce, can interfere with the important need of the food to neutralize harsh chemicals in the detergent.

Soaking glass in vinegar for a few minutes will soon indicate if it is a etched glass problem or a hard water problem.

Seems like we can’t win. Good luck with the dishes!

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