Perform regular maintenance
It's funny to say that you need to clean the dishwasher since you purchased it to do the cleaning for you. You should look inside your dishwasher for bits and pieces of food and clean out your filter to keep this from clogging the spray arms. Wiping the door down including the door gasket helps ensure a good seal when washing. For those of you that have plastic tub, the walls normally do remain wet since plastic does not absorb heat to get rid of this moisture. For those of you with a chrome tub, you will notice water spots buildup mainly on the door. To clean this, you can grab a towel and wipe the sides down a couple of times with some white vinegar. Feel free to run your machine once or twice once in a while on empty using vinegar as well. This helps sanitize your machine which gets rid of smells and cleans your machine while doing so. To do this, start an empty cycle, wait for the drain pump to activate, and wait for the water to fill up. You know it's done filling when the machine begins to circulate the water splashing it around. Open the door slowly and pour the vinegar in. Close the door, press start or resume, and let the cycle complete.
Another option would be using Affresh for dishwashers. You grab a tablet of Affresh and you place it in the detergent tray and run an empty cycle. If you feel like you have too much build up, then I suggest you toss a second one in on the bottom of the tub.
Have an error code?
Write down that error code and call for service. You can find more information about the error code by doing a Google search for the model number along with the error code. This usually will point you in the right direction.
Won't start?
No power, if power is present then check to see that user interface illuminates, if not then bad user interface or control. Another cause can be bad door switch.
Won't drain?
Clogged air gap or sink drain. Clogged drain hose, damaged check valve, or bad pump. If all else is good then bad control.
Won't fill?
Check for water supply and make sure that its on under the sink. Check for kinks in the line if it's recently been installed or moved. Listen for water valve operation. If it doesn't click on towards the start of the cycle, then bad water valve. Check overfill float in unit (some units).
Loud noises?
Foreign object stuck in drain pump, louder than normal recirculation pump going out.
Stops mid-cycle?
Broken door latch, tripped circuit breaker, broken heating element, failed sensor, bad vent fan, bad control.
Not cleaning dishes?
Improper loading, low water temperature, improper detergent amount, detergent dispenser failed, spray arm, or recirculating pump failed.
Dishes are still wet at the end of the cycle.
Try using rinse aid if you're not already, failed dispenser failure, broken heater element, broken vent fan, bad control board.
Leaking water?
Damaged or missing door gasket, damaged door hinges, leaking heating element, stuck spray arm, cracked water supply line. Bad motor gasket. Wear and tear on the hoses under unit.
Have suds in your machine?
Use about a half cup of vegetable oil during an empty cycle to get rid of the suds in your machine. You never want to have suds in your machine because this causes foul smells. To do this start an empty cycle and wait for the drain pump to activate and for the water to fill up. You know it's done filling when the machine begins to circulate the water splashing it around. Open the door slowly and pour the oil in. Close the door, press resume or start, and let the cycle complete.
Additionally some models dispense too much jet dry which in turn causes excessive suds. Jet dry can be adjusted on the detergent box on some models. Other models it must be adjusted in the control panel.