Dishwasher leaving Baked on Residue on dishes

Causes and Solutions

• Incorrect or damaged detergent.  You must ensure that your detergent is stored in a cool, dry place, and you do not keep it for too long.  If the outer box is damp it is very likely that the detergent will not be effective anymore, and you may as well just throw it away.  Buying low quality detergent can also mean that you will not get the cleaning results you require.  It is always a good idea to try out a few different types and brands – look for free samples – and this should help you decide which gives the best results for your dishwasher
• Insufficient or no Rinse Aid or Salt.  Many people believe using a 3 or even 4 in one product means you no longer need to add rinse aid or salt, but this is a fallacy.  In order to keep your dishwasher performing to its best, you should always add both these items when called for by your appliance.  It may well be that you use much less if you are using a combined product, but you will really notice the difference when you use both rinse aid and salt.
• Pre-soaking dishes before placing in dishwasher.  Casserole dishes are the biggest culprit of baked on residue, this is because they tend to overspill during cooking and this then gets baked on, especially round the top of the dish and on the lid.  The best thing you can do is to pre-soak in hot water with a liquid detergent, the hotter water the better as it will help to lift off the marks.  You may need to give it a rub over with a scourer to lift off the worst of the residue.  Once this has been done place the item in your dishwasher and run the cycle as soon as possible.  The quicker the better.  Please be careful to rinse the liquid detergent off as you don’t want foaming during the dishwasher cycle.  Obviously its not just casserole dishes that are affected, but the same principle applies.  Alternatively you can put the dish into the dishwasher and run a pre-wash programme in your appliance.
• Correct programme selection.  It makes sense that if you are just washing items from a light meal for instance, that you will only need to run a short programme, however, if you have pots, pans and many plates it would be necessary to use a much longer programme.  This gives your appliance the time to deal with this heavier wash.
• Regular maintenance.  It is a good idea to regularly clean your dishwasher, empty and clean the filters and check the spray arms have not become blocked.  If you carry this out regularly you will limit the amount of rejects you get from a wash.  It may also be useful to run one of the branded dishwasher cleaners through every now and then to ensure the inside of the appliance is as clean as possible.
• Correct loading of the dishwasher.  You should try to avoid overloading the appliance, as this will only result in a poor finish.  Try to ensure there is sufficient space around each item to allow the water to be sprayed efficiently.  It is more economic to run two washes than to try to cram it all in in one go and have a failure.  It is a good idea to rinse off any heavily soiled items, such as plates and saucepans.  This should also help to give you the end result you want.

When cooking, perhaps you could turn the temperature down slightly to try to avoid the situation arising in the first place.