How can I fix my dishwasher not cleaning properly?

[DaveC426913]

I've had this GE dishwasher for a couple of years, and things have been fine. A few months ago, it started leaving dishes dirty. I can't figure out why.

By "dirty", I mean the dishes (mostly the glasses in the top rack) are coming out with crumbly gunk stuck to them (basically baked-on from the heat drying). Otherwise, the dishes are mostly getting pretty clean. So, maybe what I should be complaining about is that my dishwaster is not rinsing properly.

I've ensured that
- it's getting hot water (run water hot first, also use 'pre-heat' wash)
- I'm running 'pots & pans' heavy-duty cycle
- I've cleaned the spray arm of any lodged gunk
- I've tried different soaps

The last thing I can think of is that my water has gone hard, and the soap is not activating properly.

Any further things to try?

 

[DaveC426913]

You know, there's nothing like writing a letter to help you think things through.

In posting this thread, I had an idea that I think might solve my problem: I checked for and found a *top* spray arm, which I've cleaned of gunk. I suspect that may have been my problem.

 

[Evo]

Dave, I suspect you are one of "those" people that don't wash your dishes off before you put them in the dishwasher. :grumpy:

I clean off my dishes before I put them into the dishwasher and have never experienced "gunk".

 

[Moonbear]

Dave, I suspect you are one of "those" people that don't wash your dishes off before you put them in the dishwasher. :grumpy:
I clean off my dishes before I put them into the dishwasher and have never experienced "gunk".

If you have to wash your dishes before putting them in the dishwasher, you might as well add some soap and skip the dishwasher entirely.

I miss my dishwasher from my last house that had a grinder in it...I never had to even worry about scraping dishes, let alone rinsing. The one it replaced used to leave "gunk" on the dishes, but it was mostly rust...the racks were rusting and the whole thing needed replacing. My current dishwasher seems to have trouble getting the detergent washed off...the "gunk" I get is definitely residue from the dishwashing detergent :yuck:. I started adding the detergent to the bottom of the dishwasher instead of the dispenser cup (the dispenser doesn't always seem to open right, and I think it might be opening too late in the cycle, so detergent is still present during the rinse cycle) and that seems to have resolved the problem.

If you're getting build-up in your dishwasher, use the powdered detergent. It's what the manufacturers recommend. It supposedly doesn't clog the lines as much as the liquid does. I know, it sounds counter-intuitive, but a plumber confirmed this for me.

 

[DaveC426913]

Dave, I suspect you are one of "those" people that don't wash your dishes off before you put them in the dishwasher. :grumpy:
I clean off my dishes before I put them into the dishwasher and have never experienced "gunk".

There has been an argument put forth that one should not rinse ones dishes first. It is the gunk that activates the soap.

 

[DaveC426913]

If you're getting build-up in your dishwasher, use the powdered detergent. It's what the manufacturers recommend. It supposedly doesn't clog the lines as much as the liquid does. I know, it sounds counter-intuitive, but a plumber confirmed this for me.

Nope. Definitely food that's not being rinsed away. Since it is almost always on the tops of the glasses in the top rack, I am almost sure the problem is due to the upper spray arm (which, until I posted that first post, frankly didn't know existed, let alone cleaned).

I've cleaned it and run some dishes and they appear to be sparkly clean. A few more loads will convince me I've solved the problem.

 

[Moonbear]

There has been an argument put forth that one should not rinse ones dishes first. It is the gunk that activates the soap.

I never heard that before, but pre-rinsing wastes a lot of water, and if your dishwasher works right, is completely unnecessary:
http://www.joe.org/joe/2003february/rb3.shtml

Dave, one problem I did run into with a previous dishwasher wasn't a problem with the dishwasher at all, but with the garbage disposal on the sink. Stuff got through without being properly ground and the drain pipe was getting clogged, so instead of the dirty sink water flowing properly down the drain, it was winding up backflowing into the dishwasher, so even when clean water was running into the dishwasher, it was getting mixed with dirty water backing up from the drain (and explained why I was only getting the problem intermittently, but with increasing frequency). I realized the problem when I wandered back into the kitchen when the dishwasher was draining and realized some of the water was also backing up into the sink. It hadn't clogged completely yet, so I didn't have the telltale flood on the kitchen floor to clue me into the source of the problem yet. Cleaning out the drain outlet from the garbage disposal solved the problem permanently.

Also, make sure your detergent is fresh and stored in a cool, dry location (under the sink in the cabinet right next to the dishwasher is the worst place for it, which is where most people put the detergent for easy access, because it gets warm and humid under there and the detergent loses its effectiveness sooner). If you're using old detergent, it won't clean as well either.

 

[DaveC426913]

Only relevant to installed, hard-plumbed dishwashers. Mine is attached to the faucet.

 

[Moonbear]

Only relevant to installed, hard-plumbed dishwashers. Mine is attached to the faucet.

Well, that rules that one out pretty quickly. You've probably already fixed it by cleaning out the upper water sprayer thingy, but in case it recurs, what about the water temperature? If you're using water from the faucet, is it hot enough for the detergent to work properly? Hard plumbed dishwashers usually have a supplemental water heater, I don't know if the one you have does. So, if you're getting colder winter weather that cools the water more as it gets to your sink, it might be dropping just below an effective temperature for cleaning.

 

[DaveC426913]

Was happening even in warmer season.

Also, as pointed out, was ensuring tap water was up to temp. as well as using pre-heat feature on dishwasher.

 

[Astronuc]

. . . . I checked for and found a *top* spray arm, which I've cleaned of gunk. I suspect that may have been my problem.

If the deposits are mineral, then perhaps the water is a bit too hard, i.e. Mg and Ca ions in the water. Perhaps adjusting the detergent will help. We use Electrasol tabs, which come in small plastic packets for individual washes.

Otherwise, the detergent can be stored in sealed plastic container to aviod moisture pickup which Moonbear mentioned.

Like Evo, I rinse the dishes first.

 

[DaveC426913]

Nope. Not mineral. Food particles.

Tried different detergents, powedr and puck.

I have a high degree of confidence that it was the top spray arm. I'll report back after a few washes and let you know.

(But Holy Jeez, thanks for all the interest and helpful suggestions! I wasn't sure if I'd get much help about such a subject here! Now I can't stop it! :) )

 

[Astronuc]

Another thought, maybe the hot water temperature is too low. I think ours is set about 120+°F which is quite hot for human skin, but our dishwasher has auxiliary heater and I usually use the hotter settings. If the water temperature is too low, the food particles will not be soft enough.

Proteins don't really soften until around 120°F (~50°C) or so, so the water needs to be a little hotter. Also, a hot pre-rinse/soak should help.

 

[Moonbear]

(But Holy Jeez, thanks for all the interest and helpful suggestions! I wasn't sure if I'd get much help about such a subject here! Now I can't stop it! :) )

:rofl: I think you've asked one of the few questions we haven't seen a half dozen times before around here.

 

[Astronuc]

:rofl: I think you've asked one of the few questions we haven't seen a half dozen times before around here.

:rofl:
Yeah! While we are on the subject of kitchen science and technology, anyone got questions on ovens, microwaves, toasters or blenders? :rofl:

 

[Evo]

I didn't mean "wash" them by hand and then run them through the dishwasher, I meant scrape the food off and rinse them, especially if you're not going to run the dishwasher immediately. I may not have enough dishes for a full load for days. The Spawn of Evo puts dishes into the dishwasher with enough food left on them for a decent meal, glad it's not at my house.

I just cannot put dishes covered with food into the dishwasher. I usually just wash by hand now anyway.

 

[hypatia]

Is there a drain trap, that needs cleaned?

 

[Bystander]

Rinse before loading? Or, just use the thing as a garbage disposal? Moonbear's article on water consumption does NOT include dilution factors for the various steps in the machine cycle; just running a bare-bones wash-rinse-dry sequence with a 95% efficient drain step following each "wet" step, you can figure on 0.3% of the "crap" left on the dishes is being dried into the machine and onto the dishes.

We rinse, too.

 

[Homer Simpson]

dishwasher not cleaning

Sometimes you have to just breakdown and buy her flowers and let her know how much you appreciate her.

 

[DaveC426913]

Bwahahahahah! :rofl: :rofl: :rofl: :rofl:

 

[Moonbear]

Rinse before loading? Or, just use the thing as a garbage disposal? Moonbear's article on water consumption does NOT include dilution factors for the various steps in the machine cycle; just running a bare-bones wash-rinse-dry sequence with a 95% efficient drain step following each "wet" step, you can figure on 0.3% of the "crap" left on the dishes is being dried into the machine and onto the dishes.
We rinse, too.

Well, the dishwasher in my last house was designed to be like a garbage disposal too. Not that you'd leave huge chunks of food on the dishes, but you didn't have to worry if there was a little bit of food still stuck on after you scraped the dishes. It had an actual grinder in it (it even demolished the unpopped popcorn kernels left in a bowl, though that made quite a racket...I had to do it just to see how good it really was ). That's unlike the ancient 1980s era dishwasher I had before that where even the smallest bit of food just stayed in the bottom of the dishwasher to be splashed back onto your plates over and over again; if I put a plate in with tomato sauce on it, everything came out tinted orange, which was why I replaced it (the rusty racks were the other reason). With those older dishwashers, you did need to pre-rinse, and I don't think people have broken that habit despite having newer dishwashers that no longer require it. You're only supposed to scrape dishes now, you don't have to go to all the trouble of rinsing them. By the time you've rinsed each individual dish, it really doesn't seem to take that much extra time to just finish washing them by hand. At that point, you might as well do what one of my friends does, which is to use the dishwasher as a big drying rack for all her hand-washed dishes.

 

[Evo]

By the time you've rinsed each individual dish, it really doesn't seem to take that much extra time to just finish washing them by hand. At that point, you might as well do what one of my friends does, which is to use the dishwasher as a big drying rack for all her hand-washed dishes.

Yep, that's what I do now. I love that green apple dishsoap.

 

[krab]

Listen to Hypatia. In my last 3 dishwashers, there is a trap for food particles. If you don't have a food grinder built in, or even if you do, and it is worn out, you have to clean this trap out. It is under a cover usu held by 2 bolts. Especially problematic are bread tabs, and other bits of flat plastic. These get sucked up against the screen and block it, preventing the pump thing that recirculates the water from attaining full water pressure to reach your top shelf dishes.