This labor-saving appliance would be sorely missed if it did not function properly. The main thing to keep in mind with your dishwasher is that what you consider to be normal usage can be damaging over time. Properly loading the dishwasher and giving it regular maintenance checks will help to make sure a problem doesn’t develop right under your nose. Review the following checklist to ensure you are not up to your elbows in dirty dishes when you could be doing something more enjoyable.
Inspect the door gasket or seal on your dishwasher for damage or defects and replace it if necessary. A leaking door seal can be frustrating and also cause expensive damage to your floor. Regularly clean it with soap and water to keep a watertight seal.
Load your dishwasher carefully so as not to damage the racks. They are typically constructed of steel wire and coated with a vinyl material that can be damaged with rough use. Dishware that has sharp edges can cut through the vinyl coating and expose the metal wire, causing it to rust. Vinyl repair kits are readily available: recoat any affected areas before they become too rusted. Both lower and upper racks normally have wheels or rollers that are easily replaceable as well. Dishwasher racks are easy to replace but are often expensive, so keeping them in good shape can save you money and prevent one more appliance from ending up in a landfill.
Check the operation of the detergent and rinse aid dispenser. Make sure that the detergent dispenser door latches tightly but opens during the wash cycle. Keep the rinse aid dispenser full and ensure that the cover fits tightly. Look for any signs of a water leak in the area of the dispenser as well. These parts are easy to replace: accessing them usually just involves removing the inner door panel.
When your dishwasher is running, listen for unusual sounds like grinding, rattling, or scraping noises. Foreign debris such as broken glass or bone fragments that enter the pump area can cause serious damage to impellers, seals, and filters. At the first sign of any unusual sounds you should discontinue using the dishwasher and have the symptom checked out.
Source - Steve Ash, Fix.com