As engineers we often get faults reported that are nothing whatsoever to do with the actual appliance, in fact it may well be the detergent used that can cause faults!
The thing to remember about all these products is that they are an important part of how your machine, be it a dishwasher, washer or washer dryer works. Companies like Lever Brothers and Proctor and Gamble who produce brands like "Ariel", "DAZ" or "Fairy" put in hundreds of thousands of pounds into researching and developing these products to work properly, please bear this in mind when you next buy powder.
There is more to it than just charging more for the product, we can assure you we have seen some disastrous results of cheap powder.
Soap powder is probably the best way, in our opinion, of using a detergent. It's relatively cheap, effective and you can choose the dosage you want to use and this is where the new tablets are not so good.
The dosage required varies according to the hardness of the water in your area and this varies enormously throughout the UK. In Scotland, for example, you would have to use about a quarter of a cup of detergent to fully clean a load of lightly soiled clothing. Meanwhile to do the same wash in Southampton you would need a full cup! It's up to you as the customer to experiment with the dosage and find out what suits you and is as economical as possible.
With the concentrated powders and liquids (especially the liquids) be very, very careful with the dosage it is very easy to "overdose" and this can lead to very serious problems.
Another important point to remember is that most modern washing machines use much less water than they used to, to be ecologically friendly and many have detergent recovery systems of one form or another, so you need less detergent therefore costing you less money.
Basically if the detergent is not fully dissolved because there is insufficient water for it to dissolve in and so it "lies" in the machine and slowly congeals to form a mass. This congealed mass of detergent can smell extremely bad, so much so it can make people vomit, and eat it's way through pump seals and aluminum drum supports; you have been warned. The solution is simple, just be very careful with your dosage and follow the instructions.
A sure sign of "overdosing" when using soap powder is a congealed mass of soap in the soap box, check yours out is it clean?
If you do use these products run your machine through a boil wash once a month with nothing in it and just watch to see how mush soapy suds you see and bear in mind that that is detergent gone to waste! Remember, you paid to waste it!
The other very important thing to remember about using to much detergent is the ecological impact of not only the additional unnecessary pollution you pump into the sewers, but also the pollution to produce the product you are polluting with.