Why doesn't my dishwasher actually wash the dishes?

July 6, 2021 4:13 PM

Bosch 300 had one job...

We replaced our old broken dishwasher about a month or so ago with a Bosch 300. We love how quiet it is and we like the third rack, but we're regularly having to re-wash dishes and flatware by hand because the dishwasher is not getting them fully clean. We're seeing a film on some of our dishes and some of them still have leftover smears of food. We're also seeing leftover coffee stains in mugs. Re-washing wastes more water than rinsing before dishes go in to wash and it's getting kind of frustrating that an appliance designed to reduce water use is resulting in us wasting more.

We currently:
-Use rinse aid
-Use a hard water booster powder
-Use a liquid detergent
-Have corelle plates and fiestaware mugs (don't know if that matters)

Have you had this issue? What worked?

posted by donut_princess to Home & Garden (29 answers total)

Response by poster: Also we already read this question
posted by donut_princess at 4:14 PM on July 6, 2021 [2 favorites]

How much pre-rinsing/washing are you doing with your dishes? What I've read about newer dishwashers is that they detect dirt and clean accordingly. If you do a lot of prewashing, they won't detect as much dirt and don't clean as well. It's counter-intuitive, I know. With my new dishwasher, we had to experiment to see how dirty we should leave them.

If that's not it, I wonder if it's worth calling the company or installer? Maybe there was a problem with the installation or with this machine. It's still so new.
posted by bluedaisy at 4:21 PM on July 6, 2021

I have not had this specific issue, but I have definitely noticed significant differences in effectiveness with different detergents, so it might be worth experimenting with that. I have had an efficient German dishwasher (Miele) for several years, and it gets our dishes cleaner than any other dishwasher we've ever had. FWIW we currently use Cascade Complete powder, along with Miele's rinse aid and salt.
posted by primethyme at 4:21 PM on July 6, 2021 [2 favorites]

Best answer: We have a Bosch. Check which wash setting it is on; not a super intuitive UI. We also had a very bad experience with an off brand detergent that built up a film all over our dishes and the inside of the dishwasher, ultimately clogging the trap. Took a lot of elbow grease to correct. It pains me but we are back to name- brand liquid detergent and rinse aid which has been like night and day. Ours is medium- sensitive to how we load it- putting really big stuff on the bottom can block too much spray and so I’ve stuck with hand washing anything larger than a dinner plate.
posted by q*ben at 4:29 PM on July 6, 2021 [2 favorites]

Counterintuitively, rinse aids seem to make my dishes less clean and leave an unfortunate wet-dog smell behind. I get excellent results from just Cascade powder and Lemi-Shine Dish Detergent Booster, which is some kind of citric acid dust that makes the detergent bubble like mad when you add both to water.

I have also had to learn to wipe off any kind of fat-based compounds, like almond butter or avocado. No matter what I do, my dishwasher can’t cope with them. Is there any commonality to the food that gets left behind?
posted by corey flood at 4:31 PM on July 6, 2021

1.) don't rinse your dishes beforehand- modern enzyme detergents need a film of crud to work properly
2.) use the pre-wash detergent compartment
posted by oneirodynia at 4:42 PM on July 6, 2021 [3 favorites]

Is there anything plugging up the sprayers? When I've had issues with dishes not getting clean, there's often been some gunk in the spray holes. (Cooked mushroom is the worst.)
posted by tchemgrrl at 4:45 PM on July 6, 2021 [8 favorites]

I would try a different detergent, and possibly going with pods instead of liquid detergent. After reading previous dishwasher posts I checked to see if my dishwasher has a place to put in some liquid detergent in addition to the pod. It does but I've never used it because my dishwasher is already getting the job done with the pods alone.

Seconding cutting down on the pre-washing/rinsing. I will just scrape/wipe off anything solid but otherwise leave my dishes alone when I put them in and they come out fine.

How is your dish spacing/placement? I find myself re-arranging the dishes if someone else has loaded the dishwasher to make sure that nothing is touching anything else. Sometimes this means removing certain dishes because they don't work well in the dishwasher, like bowls that are too deep, but Corelle plates should be perfect.

How often are you running your dishwasher? If stuff is sitting in it for too long maybe its drying on and harder to clean? Mine gets filled up and run every day.
posted by any portmanteau in a storm at 4:49 PM on July 6, 2021 [1 favorite]

Check the drains and food traps that they don’t have any packaging or broken glass or whatever either.
posted by Crystalinne at 4:50 PM on July 6, 2021 [7 favorites]

Mine had something wedged into the bottom sprayer so it didn't rotate freely. Also, the drain filter was more complicated than I thought, and I was only cleaning the outer filter, but there was another one under it that needed cleaning.
posted by lab.beetle at 4:58 PM on July 6, 2021 [3 favorites]

Best answer: I use the highest-end dishwasher soap pods (either finish quantum max or cascade platinum) plus jet dry. You might also double-check that the trap at the bottom is seated correctly (the two arrows should match) and not gunked up.

(I have a Bosch. Not sure what number. But it cleans like a champ, except when the filter trap at the bottom is clogged up.)
posted by leahwrenn at 5:13 PM on July 6, 2021 [5 favorites]

I've always used the Finish dishwasher pods that Bosch recommends and haven't had an issue. FWIW, we have very soft water, do not pre-rinse or typically use rinse-aid. But yeah, check that the trap is clean and locked in place and that you're not positioning things so as to block the free rotation of the spray arms
posted by mumkin at 5:47 PM on July 6, 2021 [3 favorites]

Basics first: Is it getting hot water?
posted by artdrectr at 6:14 PM on July 6, 2021 [9 favorites]

Run your hot water for a minute to get it up into the pipes. That makes a big difference with my Bosch.
posted by pearlybob at 7:04 PM on July 6, 2021 [7 favorites]

It sounds counter intuitive, but you may well be scrapping your plates too well. Modern detergents need dirt on your plates to work, as counter intuitive as it is. You want to get the solids off, but you don't want to be pre rinsing before hand.
posted by wwax at 7:34 PM on July 6, 2021

Best answer: Our Bosch doesn't have a prewash detergent container, so we weren't adding detergent to the prewash. I saw the video that was linked on Metafilter about how much work can get done in the prewash, *especially * if there's detergent in the prewash. So we started throwing a little detergent into the main compartment (in addition to putting it in the detergent dispenser). My filter certainly is less gooky since that change and no complaints on the dishes....
posted by Tandem Affinity at 7:53 PM on July 6, 2021 [2 favorites]

We have had a Bosch 865 for 3 years and very hard water. We use the Casade Total Clean pacs without additional rinse aid and it really works well using only the "auto" cycle.

My suggestions: Check the strainer (basket under the screen on the bottom), take the spray arms off and try to back flush anything out of them (I had some corn kernels that somehow got in there and made things not get clean), make sure the arms can freely spin every time you load, make sure the water going in during the wash cycle is REALLY hot.
posted by ArgentCorvid at 8:10 PM on July 6, 2021

So I found that when I used cheaper pods my newish dishwasher barely cleaned dishes. I usually go with cascade platinum and it works way better.
posted by Ferreous at 8:20 PM on July 6, 2021 [1 favorite]

Best answer: As the author of the question the OP linked to in their first comment, I gotta say, I'm having the exact opposite experience with my Bosch 300. In the two-and-a-bit months we've had it, it has only failed to clean one dish we've thrown at it, a Pyrex that we made hash in that I inadvertently let sit dry for a couple days before throwing it in the machine (some of the food basically baked on). Otherwise, it's worked great. Here's what we do:

- Use Cascade Platinum detergent pods and rinse aid
- Run the kitchen sink until the water is hot before starting the dishwasher (this tip is from a video linked in the thread you linked to above)
- Clean the strainer/filter once a month, and give it a visual check in between for bigger chunks of food
- As others have mentioned, we do not pre-rinse our dishes, we just throw 'em in

So maybe switch from liquid to pod-based dishwasher detergent as a first step, see if that works better. I love Cascade Platinum but it's also the only one we've used with this dishwasher so I can't say anything comparative, but CP does really good work.

use the pre-wash detergent compartment

Bosch, famously, doesn't have that feature, as they claim their dishwashers are efficient enough not to need it. And in my experience that's true, but maybe as others have been saying, detergent brand matters.
posted by pdb at 8:23 PM on July 6, 2021 [2 favorites]

Best answer: Our Bosch dishwasher was leaving soapy film on the dishes for awhile. We noticed it after we got a new boiler and were thinking maybe the hot water wasn't showing up quite when the dishwasher needed it. After some trial and error we did the following:

- switched to liquid detergent (cascade complete, I think) so we could easily
- use less detergent
- and, critically, turn on the "extra shine" setting on the dishwasher

The extra shine cycle adds an additional very hot water rinse, which seems to compensate for whatever sluggishness the boiler was adding into the system.
posted by potrzebie at 8:47 PM on July 6, 2021 [1 favorite]

Another Bosch 300 user who has no issues whatsoever and it is by far the best dishwasher I've ever used. We use Ecover dishwasher soap tablets along with Jet Dry rinse aid, only scrape off large chunks of food, and use the "Auto" cycle. Our water is moderately hard, around 150ppm. We don't run the hot water first but the dishwasher is about 10 linear feet from the hot water heater. The filter gets cleaned out every month or two. The filter gets a little ooky but it's a small price to pay for washing measuring cups covered in coconut oil and having them come out clean. Bakeware or table knives with hardened food bits sometimes need a little bit of extra cleaning but it is rare. Avoid the "quick wash" as it will definitely leave schmutz on your dishes.
posted by Brassica oleracea at 9:04 PM on July 6, 2021

You need hot(ter) water. Dial up the heat on your water heater; you'll get cleaner dishes. Take care when taking hot showers or washing your hands, though.
posted by They sucked his brains out! at 12:44 AM on July 7, 2021

I have a different brand of dishwasher, but two things that helped me (which are mentioned in that 30 minute video that's linked in the other question) are: (1) running the kitchen sink until the water is hot (to make sure the dishwasher starts with hot water), and (2) putting detergent into the pre-wash receptacle (or just squirting some into the tub if there's no receptacle). I just use ordinary Cascade detergent; nothing special.
posted by ambulatorybird at 3:38 AM on July 7, 2021 [1 favorite]

Watch this video.
posted by Akke at 5:46 AM on July 7, 2021

another idea i had overnight: if you have (or can borrow) a GoPro or other waterproof action camera, you could put it in the dishwasher to see what is going on during the cycle.
posted by ArgentCorvid at 7:25 AM on July 7, 2021

I disagree with most of the advice here. First, a Bosch 3000 series has Flow-Thru Heater (TM) for heating the water - so turning up your hot water heat or running your sink first is just wasting electricity or gas. It washes at temperatures between 160F and 140F, so if your hot water heater is turned up high enough to support that, it's a health hazard.

Secondly, they have multiple settings - normal/auto so if you are choosing 'normal', it is not sensing the amount of debris in the water to make a determination about cleanliness, so that's not it either.

The answers about detergent might be correct: The manual states that if you have hard water, then you need to use more detergent. If you have soft water you need to use less.

If you have stuck on food, it also recommends the PowerWash cycle.
Beyond that, it's a dishwasher, and some stuff may need pre-rinsing or to be washed twice.
posted by The_Vegetables at 8:01 AM on July 7, 2021 [1 favorite]

Seconding that you don't need to adjust your hot water as Bosch dishwashers heat water to the required temperature. In fact, ours is hooked up to cold water and works just fine (though it takes longer).

In my experience, issues with things not getting clean have either been a clogged filter, something stuck in one of the sprayer arms (take them off and run some water through them) or something blocking the sprayer arms from spinning properly. Detergent also makes a difference, but your problem sounds like something more serious.

I believe the 300 also has a sensor to check how dirty the dishes are and will adjust the wash cycle on this basis (it detects how opaque the water is after the first rinse), so if you're pre-rinsing, don't do that.
posted by ssg at 9:27 AM on July 7, 2021

Another vote for Cascade Platinum pods.

The default wash setting is the one the manufacturer has put the most work into optimizing. I mostly only use the “normal” setting on my dishwasher.

Last but not least, we sprinkled a bunch of borax powder into the door of the dishwasher before running it last time and they came out sparkling clean, better than they have ever been before.
posted by music for skeletons at 12:09 PM on July 7, 2021

I have found newer dishwashers (which have to meet some pretty stringent eco requirements, to my understanding) don't wash well unless you put them on the ultra hardcore cycle, so if some of the above advice doesn't work, maybe try that?
posted by nosila at 1:15 PM on July 7, 2021