Water quality (hardness, mineral content, etc.) certainly influences a DW's cleaning ability. Some DWs can adjust for hard water; others can't. Some DW detergents seem to work better in hard water, according to CR.

These factors are relevant to how well your DW works, perhaps even more strongly now than several years ago.

A few years ago, the federal govt. banned phosphates in DW detergent and suddenly a lot of DWs stopped working well in areas with hard water. You probably need to experiment with different detergents. I find that Quantum Finish works really well - a little more expensive than some detergents but worth it.

You may have a difficult water source if it is unique.
Miele makes dishwashers and the cleaning products, detergent, rinse aid and softening salts that should give you a good shot at using your water to get things clean.
If you rely on municipal water source commercial establishments in your area might have a recommendation for a detergent you could try with your existing machine.

I've never had a dishwasher that cleaned dishes anywhere as well as I can do it by hand. That's going back 20 yrs, and in three different countries. My current Meile Optima is the best of a sorry bunch, but my tea cups are still stained, and there are some things I just don't bother expecting it to clean. For me, a DW is a convenience that gets most of my stuff sorta clean enough, but we always do a sink full of hand washing every evening.

I really don't think it's hard water. I've had at least 3 previous dishwashers in this house and they've all worked fine. This one doesn't clean at all. The slightest amount of food left on dishes will be there when the cycle is complete. A glass used for iced tea will come out brown if you don't wipe it with a sponge before putting it in the dishwasher. I also assumed in the beginning that I must be doing something wrong or something was defective. That was why I had 2 different service people out. The bottom line is that this machine just doesn't clean. I'm more than willing to buy another one but I can't find one that doesn't have bad reviews with the good.

Could be low water pressure, or low temperature. Our DW heats the water but we have our water heater set pretty high anyway. We have an e-Lux DW and haven't had any problems with cleaning.

There has to be something wrong somewhere. Appliance manufacturers have no reason to produce a machine that doesn't perform, even though consumers seem to want to believe they purposely do just that.

Reality also is that there's a HUGE variance in consumer habits regards to dishwasher use ... what goes in compared to how they expect it to come out.

As others have said, detergent choice also is much more crucial nowadays in matching to the local water conditions.

To those complaining of tea stains ... getting rid of tea (and coffee) stains requires bleach. Dishwasher detergents that contain enzymes don't have bleach, and vice versa (bleach deactivates enzymes). I bought a case (six boxes) of institutional Cascade, which has both bleach and phosphates. I alternate between it and an enzyme detergent depending on the soil characteristics of a given load. My plastic storage bowls and the pitcher for my West Bend iced tea maker are now nicely stain-free!

The detergent I'm using contains bleach. I don't think they purposely manufacture something that doesn't work. I think their quality control is poor and whatever has gone wrong isn't something the repair people can find or recognize. There are too many people complaining about dishwashers that don't wash for all of them to be making mistakes or using the wrong detergent. Some of them probably but not all. Water pressure is good and temperature is slightly higher than recommended.

>>>There are too many people complaining about dishwashers that don't wash for all of them to be making mistakes or using the wrong detergent.

Not necessarily true. First of all, mostly people who are unhappy are the ones who post. Secondly, about a year ago, a repairman posted on this board that once they stopped adding phosphates to detergents, MANY more people started calling repair places because their DWs stopped working. There has also been a lot written about this subject. Since then, detergent manufacturers have been tweaking their formulas to get them to work better. I strongly suggest you try a different detergent. I switched from Cascade Complete powder to Quantum Finish tabs and am very pleased with the results. These tabs contain both enzymes and oxygenated bleach (not chlorine bleach).

I have a KA, which is really just a Whirlpool under a different badge. It's far better than the 1989 GE which refused to cooperatively die until I finally replaced it with the KA.

I too noticed the immediate difference when the phosphates were phased out and switched to the Quantum Finish, which restored my faith in my DW. It DOES get out the tea and coffee rings. It really does sound like your WP has something wrong with it. I will say that we have an extended warranty and of the 4 servicepeople we have had, two of them were absolutely useless. One wired a replacement part in backwards, in fact!

It has only 2 issues: greasy tomato sauce doesn't really get bleached out of plastic containers (they stay pink although they're clean) and very fine garnishes, such as parsley shreds, sometimes slip through the rinsing/filtering system.

The 2009 KA is definitely not as well made as the Miele. Unfortunately this was before Miele adjusted the racks in their newest models, and my dishes just did not fit well into the Miele with the old racking system. I have a lot of really oversized/odd-shaped dishes and pans, however.

I have the same issues when reading reviews! If I don't see any patterns or safety issues, I do feel a little better about a model, but still hard to pick.

I know GE is a controversial thing around here, but the GE DW we got in December is fantastic. Granted it replaced one that was very old and loud, but it is incredibly quiet (usually don't know DH started it until the water drains), and our dishes come out pristine. Every 3-4 loads we end up with a stray grain of rice left somewhere, but we eat a ton of rice and some of it is very starchy. We use power ball tablets.

The model we have is a Profile with SS tub, it was on sale and had rebates so I think we splurged on the top of the line model.

Since so many thought the detergent might be the problem I bought Quantum Finish today. It is an improvement. Today's load had been already basically washed by hand. Most of the glasses and cups did come out better. Still had a couple of glasses and a few pieces of other things that weren't clean, but I'm hoping it will be enough of an improvement that I can stand it for a while longer. I hate to throw away more money on a machine that does a poor job.

Just a vote for DW cleaning. I'm amazed that cooksnsews gets cleaner dishes by hand washing. Certainly not my experience, though that may reflect my poor hand washing skills. I will say that over the last 15 years, between the two houses, we have owned four Bosch and two Miele dishwashers. All of them did a great job cleaning when used with the right cycles, detergent, rinse agent, and water source. We use dishwashers a LOT--we have three in the main house, two Mieles in the kitchen and an overflow Bosch in the basement for entertaining, and we have no tea/coffee stained cups, no greasy tupperware, etc.

And, to add more heat to the discussion, it should also be mentioned that dishwashers use much less water, and energy to heat that water, than typical hand washing. Miele's currently use under six gallons per cycle, and as little as 1.2 gallons in the economy cycle. Depending on how it's done, hand washing can use over 2 gallons per minute, adding up to dozens of gallons per wash load. Just something else to enter into the equation.

My parents bought a prefab vacation home in the mountains (the Sierras) which included the cheapest appliances known to man & woman. I urged my mother to upgrade her dw (nondescript generic brand I had NEVER heard of), but it turns out it worked GREAT--better than my beloved, high-performance Miele. I can only assume the reason her dishwasher worked so very, very well was because her prefab house and water pipes were so well insulated that the water pumped into and onto the dirty dishes was INSANELY hot (not that her water heater was set too high--water coming out of the sinks/showers didn't cause burns). She also added a water softener to her plumbing infrastructure, but I think it was the temperature of her water that made her dishes come out so very,very clean. Try ramping up the heat on your water heater (?) and be sure to use a high-quality detergent/rinsing agent combo.

Well, I can wash a lot more dishes than my Meile can with 6 gallons of water, since hand washing can be a continuous operations, while the DW works in batches. The trick is to shut off the taps while you're washing. I can do it much faster, as well, especially if I have a helper to dry. The Meile heats water with electricity, while my main water heater uses gas, which is a lot cheaper here. I use all the recommended detergents, rinse agents, and salt. I didn't notice any difference when we switched to non-phosphate detergents - performance is just as sorta OK now as before. As I say, a DW is just a convenience that I can afford to have, so that I can use the two hours it cycles to do something else.

Just because the WH is set hot enough (130-150f) doesn't mean the DW gets hot water. These new machines do not use as much water. Consequently if your kitchen is a long way from the WH, they fill with cold water.

I now always pre-run my hot water at the sink before starting the DW to make sure the water is hot before the fill starts.

I also check the water level to make sure it is touching the heater element when full. I also use the 'Hot Scrub' option which heats the water even more.

We get very clean dishes with a cold water hookup, Cascade, and RinseAid, using a Miele DW.

I have an Electrolux that we put in our new house two years ago. It cleans phenomenally. I use cascade "pillows" and never rinse them and never use the heat cycle to dry. I personally don't like the way It loads but I also have odd sized casseroles and cookie sheets etc. they don't fit. I liked my old kitchen aide better.

When the phosphates were taken out, my low-end Miele suddenly didn't clean anymore. Now I use Finish (wish I didn't have to,) and Lemishine which is basically citric acid, and it is fine. Yes, it's the hard-water-and-no-phosphate problem.

My 14 year old Kitchen Aid cleans everything and anything. It's still going strong and I never have cup stains. I just can't imagine dishes not coming out clean in a new dishwasher. Something is not right. The only time I ever have a problem is if something was burned on and needed to be hand scraped with steel wool or something. But I never even use the heavy duty cycles. On the other hand on vacation recently I used a dishwasher that was just awful and didn't get dishes clean at all. It didn't look to be that old, it was disgusting so I feel your pain and hope you can get something that works for you. I am afraid when it's time to get a new DW that there will be nothing like the quality of the old ones even if I get another KA. It seems like nothing is well made anymore. It's upsetting to say the least since they cost more now too.

Whirlpool and Kitchenaids are made by the same company. Here are a couple of things to checkout if you have not already. When we first got our Kitchenaid Dw they said that it had a hard food grinder. We took them at their word, at least our kids did. They ran the dw with chunks of food on the plates and bottles with labels. We were having problems (after 2 years) and the repair guy showed me how to get to food grinder. There was all sorts of stuff stuck in it. Bottom line its not a food grinder, but our dishes did get cleaner after we cleaned that piece. We also had to clean out all of the spray arms. I also ran dishwasher magic twice thru the machine.

Ultimately after 7 years we determined that the pump was failing and I actually bought the top of the line Kitchenaid DW without the food grinder which we love. The funny part was that 7 years ago I thought the food grinder was a must have.

Good luck. I am currently on the hunt for a new dryer which I plan to post over in Laundry.

I have found that with my "new" Whirlpool dishwasher I have to buy the most expensive detergent (cascade complete pacs) and use the longest cycle (pots and pans) to get the same cleaning that the Wal-Mart powder using the normal cycle provided on my old one.

Part of it is the normal cycle is severely restricted to get a good "energy star" rating and part of it is the phosphate removal.

So I still get good cleaning but it takes forever. I fully expect my next dishwasher to clean poorly once the latest water and energy requirements kick in. I'm almost tempted to buy another now and put in into storage.