Dishwasher-why are my dishes still dirty

Dishwasher – why aren’t my dishes clean? 

Common Causes

 One of the most common causes for dishes to not be cleaned thoroughly is that too much food residue has been left on plates before they are loaded into the dishwasher.You must scrape food residue from the plates and, in some cases, rinse the dishes first.  

Some foods are particularly sticky, porridge and fried egg for instance, and it is advisable to always rinse these plates.  If you don’t, you will commonly see hard-baked food left on the plate which will require cleaning under very hot water to remove.

Some people may think that you might as well not bother with a dishwasher if you have to rinse the plates first, however, it has been proven that this is not the case.  The temperature of the water used in your dishwasher is much hotter than you would normally use for the washing up.  Not only that, it is much more hygienic as you do not need to dry the dishes with a tea towel.  Tea towels are known to be carriers of germs, which get transferred to your plates.  At the end of the dishwashing cycle, the plates are steam dried at extremely high temperatures, leaving your dishes clean and almost sterile. With the modern dishwashers, the usage of water is lower than needed for washing up in a sink and you also avoid having to heat water just for washing up. Instead of washing up after every meal, you can generally clean a family’s daily crockery and cutlery items in one wash cycle.

Another common cause for complaints that plates are not clean at the end of the cycle is that people tend not to read the manufacturer’s instruction book on the best way of stacking your machine to get the best results.

Unless you load your machine correctly, the water spray is not getting to the crockery in the right places and with sufficient force.  A good tip is to always place pots and pans in the bottom tray, as the water spray is designed to deal with a heavier item than in the top tray.  The top spray is designed more to deal with smaller plates, cups, glasses etc.  

In most dishwashers you will find the only place to fit the cutlery basket is on the lower layer, again the spray pattern has been designed to deal with food residue on your knives and forks.  As you do with the sticky residue on plates and saucepans, some of your cutlery items may also need a quick rinse before being loaded into the basket. The decision on what needs to be rinsed prior loading in the dishwasher is something that you will become familiar with and  you will soon know how to get the best results from each wash.

General Maintenance 

You can certainly carry out a few regular tasks to help keep your machine in tip top condition.  If the standard of finish starts to drop, one of the things to check is the spray arms which, in most cases, are very easily removed.  The small spray holes can get blocked occasionally, rice being a particular culprit, and it is very simple to rinse them under the tap to clear any small blockage. Fill the arm with water before replacing it in the machine to ensure that all the spray holes are clear. If not you may need to clean the arm again.

You should also check the filter at the bottom of the machine to make sure this is not being blocked by food particles.  This is also very simple to remove, and just requires rinsing under the tap.  If it is more clogged you may need to use a mild abrasive cloth to help to remove the debris.  If you find that your filter is badly blocked, you may decide to start to rinse a few more items prior to loading them in the dishwasher, as this will definitely reduce any blockages in the future.It is important to keep the filter clear as not only will it keep your machine fresher, it will help to avoid issues such as blocked internal fill chambers, and also avoid the need to call in a service engineer to resolve the problem for you.

Correct Detergent Selection 

This is obviously a personal choice but you may wish to bear in mind that the powder tablets can cause problems, and if not dissolved completely can leave a nasty residue, plus insufficient cleaning agent will be used during the wash cycle.  This can leave your dishes feeling sticky and dull.

In order to help with this situation, the use of Rinse Aid is strongly recommended, even if you are using a product that supposedly doesn’t require additional Rinse Aid.  Most people will use a Rinse Aid when called for by your machine, as you will see much better results, especially on glasses, as they won’t be streaky and will have a better sparkle.

It is also a good idea to dose the machine with dishwasher salt as this also improves the quality of cleanliness you can expect from your machine.  Just follow the indicators for when to add the salt or rinse aid, and you should see an improvement.

In general terms, if you look after your dishwasher, you should have a fairly fault-free experience and it should last for years.  There are obviously problems that can arise, but if you check the steps identified above before calling in an engineer, you should be able to avoid an unnecessary call out and the fees that go with it.



Disclaimer: The information provided has been prepared as a guide only and the steps taken are likely to vary for different appliance models. We strongly recommend using a qualified engineer to undertake major repairs and fault finding.


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