"Big three" causes of change you described are...

1) Incomplete fill

2) Water not getting hot (120+F)

3) Obstructed drain path.

All are easy to check and usually easy/cheap fixes. I'm not there but even from cyber-distance, I'll bet your problem is one of those. "Dishwasher Cleaners" are band-aid solutions that can hide problems for a little while but often cause other problems themselves. I think that's what you're describing.

Pretty much what asolo said with one addition.
I've found that depending on how heavy the hard water and detergent deposits were, that it may take 2 or 3 cleanings to get rid of it all. Sometimes the 1st cleaning just softens it up. I haven't tried the Affresh but I usually recommend Dishwasher Magic or Glisten. I've had real good luck using either one.

jakvis....with respect......

If any of the issues I suggested are, in fact, the issue...... it won't matter how many "cleanings" with these products are undertaken.

I do not dispute that these products "work" (after a fashion) but they do NOT solve the underlying problem that causes -- and will continue to cause -- the problem described.

People have have been getting excellent results from DW's in hard-water areas using all manner of detergents for more than 50 years. IMHO, the OP has a fundamental problem that should be addressed.

asolo, That's why I agreed with your 3 steps...
But if all those check out it can be hard water & detergent deposits contributing to the issue.
I've seen reduction in water flow due to build up of deposits on the pump impellers, build up reducing or completely closing off the water jet holes in the spray arms. Some dishwashers are susceptible to build up around the pump ports. I've also seen where one treatment with a d/w cleaner made the problem worse because it just loosened the deposits but did not completely dissolve them.

Since the removal of phosphates last year I've had a major increase in calls to my office regarding d/w cleanability. We ask our customers to first check the drain anti-siphon for blockage, make sure the spray arms move freely, and suggest they try running a citric based cleaner through their d/w. If they still experience any issues to call us back and we'll run a service call. We also ask what kind of detergent they use and suggest one of the enzyme based products if they aren't already using one.

I agree that some customers can still use any detergent and get decent results. But that's becoming less and less the case.

In the 35 years I've been doing appliance service, it's been just the last year and a half that I've seen so much issues with d/w's, new and old, that we actively try to tell people that they probably don't really need a service call.

Jakvis....I yield to your experience. With that history, you certainly have a larger perspective than I do. And I sometimes overstate....as this time. Thanks for information....and for letting me off easy.

De nada

Hope the OP won't mind if I ask some follow-up questions. First, how does one check for an obstructed drain path? If the spray arm spins freely, how can one know if the pump impellers are blocked?

We bought our home (new) about 3 1/2 yrs. ago. Over a year ago, the Bosch d/w developed a foul odor. We checked for debris and ran it empty with white vinegar on the power wash cycle. Dh turned the water heater temp up (no little ones here, so it's scalding hot) and we run hot water in the sink before turning on the d/w. I've been using Dishwasher Magic, Lemishine, Glisten, and other d/w cleaners routinely during the first week of each month. Some months, the d/w requires two such cleanings. I've also used a disposal cleaner several times, although no odor has been detected in the sink. The drain loop beneath the sink appears to be as high as it can go. There's no air gap (they're just not done here and the plumber I asked about it had never installed one.)

I used the cleaner a week early this time, but the odor returned a few days later. When I tried Lemishine again, our glasses and Tervis tumblers all had a haze on them and other items didn't look clean. As the OP described, there was a white haze on two nonstick pans. I'm running the same items through another power wash cycle (third try), this time with just Lemishine (in the detergent dispenser as instructed) plus a new lemon rinse agent.

Is there anything else to try before we replace this d/w? If we do opt to replace it, can you suggest a reliable d/w that's also fairly quiet? Thanks.

"Is there anything else to try before we replace this d/w?"

Yes, certainly. You haven't described an attempt to diagnose anything. You've only described throwing guesses at the problem. If you, yourself, don't know how to check your fill-level, temperature-level, and drain path, then hire someone who does. This will be simple stuff for an experienced person.

New DW's are nice, too.

"If you, yourself, don't know how to check your fill-level, temperature-level, and drain path, then hire someone who does. This will be simple stuff for an experienced person."

Asolo, are you available for the job? If not, I'm out of luck. Seriously. I've tried the only appliance repair services here that don't have horrible BBB ratings and their guys had no clue.

Guess I'll buy a new d/w. Have been reading specs & reviews on Kitchenaid, Maytag, GE & Electrolux, all priced around $1000 - $1400. Any better than the rest?

OK...let's go, then.

Get a bucket or two and some rag-towels in case you need to wipe up. Get single five-gallon bucket or two 2 1/2 gal. buckets.....enough to hold the entire DW fill. Don't want to be surprised when the water starts to flow.

1) Disconnect the DW drain hose from whatever it's connected to under the the sink and position it so that it will drain into one of the buckets.

2) With DW empty, start up a "rinse only" (or whatever it's called on your machine) -- the cycle that fills, sprays for a minute, then drains and stops. Cold, hot, doesn't matter for this test. Just want to get the water in there.

3) Sit there with the drain hose end in the bucket bucket and watch the flow-rate when it hits the drain part of the cycle. It should really pour out of that hose-end. Be sure and be ready to hold it still so it doesn't dance all around.

4) When DW stops, we're done. Now, diagnose from what you've seen. If the water comes out quickly, you've learned the hose is not obstructed and your pump is working just fine. Look at the water that came out into the bucket. If the water is clear, the inside of your DW will be clean. If there's a bunch of crud in the water you'll know the drain has been obstructed in the recent past upstream of the hose-end you're holding. If you don't get discharged water in the amount of your DW's required fill-volume, you'll know you got an incomplete fill. If you don't know required fill-volume, just note the amount of total discharge and we'll cover that later.

5) Before reconnecting the DW hose to drain or disposal, take a look at that connection. Disposal connections, especially, can accumulate crud that's hard for you to see. I've seen them 2/3 obstructed. Easy to check and clean out. Do that before reconnecting.

This will teach you a lot in just a few a few minutes. Since you haven't done this before, I'm suspecting that it will probably take you 15-20 minutes. If you ever do it again, it will take you 5.

Please come back and tell us what observed.

Thanks for the step-by-step instructions. I'm unable to do this (physically cannot) but will ask dh or someone else to give it a go and will check back; it may be next weekend. I appreciate your efforts.

"....their guys had no clue...."

Must say I'm discouraged to hear this....from anyone. Except for the circuit-boards, DW's are not complicated machines. Even lower-level techs should know where to start looking based on what you've said here. Most of what he'd want to know to begin with he could learn in minutes by doing nothing more than what I suggested to you. I do not understand how they could have come away not knowing anything.

If you're prepared to spend 1,000 - $1,400 on a new machine, I have little doubt you'll be pleased wherever you look. Be advised that newest machines run longer than older machines -- which means whatever noise they make, you'll be listening to longer than ever before. I would shop for quiet.

I finally had a moment to check back on my original query. What a lot of wonderful information. My dh and I are relatively hopeless when it comes to diy, but based on asolo and jakvis' advice, I am anxious to test out your recommendations. I must say, it will be nice to get rid of the funky odour, not to mention having cleaner dishes. Like rockmanor, I will get back to you when I have a chance to attempt this.
Thank you both (asolo and jakvis) for your advice.

Don't know whether or not your machine has a filter. If so, I have assumed you've cleaned/maintained it and that is not the problem. If I'm mistaken about that, your problem just became really simple. Please advise.

asolo, I'm all for simple. Speaking of simple, I have a stupid question. My filter is supposed to be self-cleaning, but I don't know where the filter is to check if it is actually cleaning itself. I have checked online for the manual, with no luck. Any idea where it might be on my machine and how I would check it? You are so kind to help me.

They're all "self-cleaning".....but they all need attention once in a while. I don't know what machine you have but maybe this site will get you going. Please come back and say what found.

Here is a link that might be useful: cleaning Maytag DW filter

Asolo, I got lucky and had help to check out the d/w today. It's a Bosch SHX46A05UC/46 (FWIW.) When the drain hose was disconnected, about 1 cup of water poured into the bucket. The rinse & hold cycle was run. About another 1/2 cup of water drained into the bucket at the start, then at the end there were three distinct pumping cycles during which time a total of 16 cups (1 gal.) of water rapidly poured from the hose. While the water appeared clear, it did foam up in the bucket. The foam dispersed shortly after the draining ended. There were a few tiny black flecks of something solid that drained into the bucket; they were small enough to pass through a typical window screen. No other debris was in the water, and nothing was seen on the connection or in the hose. The filter in the bottom of the d/w was checked and nothing was in it. This all took maybe 10 minutes, most of which was spent waiting for the rinse cycle to end. I was surprised that the low volume of water, but could not locate an owner's manual to see if that's normal for this machine.

Is there anything we should try? Or is it time to start shopping online for a new d/w? Thanks!

I'm not familiar with this particular machine, but......

From your description, pump is working fine and line is clear. However, that's not enough water. I believe you've got incomplete fill. If you can locate manual and/or if someone more familiar can chime in here, I would be interested in knowing what a "normal" fill-volume is for this machine. I'll bet it's more than a gallon.

Incomplete fill controlled by module and fill-solenoid. Fill solenoids are easy/cheap replacements. Obstruction, failure, intermittent failures are common. If you were handy, I'd suggest checking the water line going to the fill-solenoid but if you're not confident, you'll just make a mess and get angry at the world.

From what you've said so far, you're either looking at a service call with a competent tech who will likely replace the fill-solenoid, the control module or both.....or you'll be buying a new machine. I have zero doubt a competent tech could make this machine 100% right but you've said your experience with local techs has been terrible so I don't know what to advise that way.

I don't know what service costs in your area but if you were where I live the cost would be $75.00 minimum plus parts. If I'm correct about diagnosis, fill solenoid valve would be $75.00 to $100.00. Modules can be in the hundreds....don't know your machine, but Bosch stuff is typically pricey.

So.....your call.....how old is this machine? I just bought a new Whirlpool almost exactly like the old one (9 years old) because the main board had to be replaced for a total cost of $275.00. It would have fixed the machine but it would still have been a nine-year-old unit with over 3,000 cycles run so it didn't make sense. I looked at the repair money not spent as a $275.00 saving on the new machine.

Wish I could be more help to you. Wish someone more familiar with your machine would comment. If you put the Bosch model number in the google window, I have no doubt you'll find pages of stuff to look at but unless you intend to DIY, not sure what the benefit would be.

SearsPartsDirect.com returns two model variations on SHX46A05UC, a 14 series and a 21 series. However, both take the same water valve, Part Number 425458, listed @ $26.24. Another parts source I use lists it $8 higher. I don't know how to determine the series of a particular specific (sometimes by 1st or last digits of the serial number) ... could be yours is neither 14 or 21 but something different from either ... although Sears doesn't list any other choices.

Search your model at SearsPartsDirect to see a parts breakdown, the valve is shown on the "Base Parts" illustration. Changing it shouldn't be difficult.

However, it's possible the valve is not bad, but simply clogged. Water valves typically have a screen to catch debris in the water supply ... and they can also get clogged with accumulated mineral deposits, or debris from a disintegrating diptube in the household water heater. Usually (but not always) the valve can be disassembled and cleaned by soaking in vinegar, Limeaway or CLR, etc, and scrubbing gently with a brush. Keep liquids away from the electrical parts of the valve, of course. The example shown below is somewhat worse than one typically finds, to the point that this valve hung open and flooded the kitchen.

--> It's also possible that 1 gallon is the proper fill level. Dishwashers nowadays are getting by with seemingly scant amounts of water per fill ... which is one reason why cycles are long, the circulation pumps spray less water force so more time is needed to do the job. My DishDrawer takes 0.8 gals, LESS than 1 gallon, per fill, and it's not exactly a "new" machine, being nearly 8 years old.