If there is still water inside of your dishwasher after it has stopped running, then you have a drainage problem. However, before you pick up the phone and call your mechanic or appliance repair technician, do a little trouble shooting on your own. You may be able to fix the problem yourself.
Clean Out The Drain Basket
The first thing you need to do is clean out the drain inside of your dishwasher. The drain is located at the bottom of your dishwasher. The drain's job is to pick up bits of food and other debris. You should clean this out on a regular basis. If it's been a while since you cleaned it out, that may be the problem.
Just take a dishrag, and scoop out all the debris that has accumulated in the drain.
Remove Drain Basket
If that does not seem to do the job, you main need to remove the drain basket to get to any food that is stuck behind it. You'll want to pull the bottom rack out of your dishwasher, and then use a screwdriver to remove the screws holding the drain basket in place. Be sure to set the screws somewhere safe.
Take out the drain. Use a dishrag or paper towel to scoop out any food that was hiding behind the drain basket. If you see or suspect that there could be food further down the drain, use a straightened out wire hanger with a hook on one end to fish around and scoop out any food that has made its way into the drain.
Use dishwashing soap to thoroughly clean the drain basket before you place it back inside of your dishwasher and screw it back in place.
Check The Drain Hose
In order to check the drain hose, you will need to remove the panel that is located at the bottom of your dishwasher, right under the door. For some dishwasher models, you can just pull this panel off. For other dishwasher models, you will need to remove the screws holding it in place.
Once you have removed the panel, get out a flashlight and check out the drain hose. If the hose has a kink in it, or is folding up all weird, that may be making it difficult for your dishwasher to drain. Try to un-do the kink or fold as best you can.
If you don't see a kink or fold in the drain line, run your hands along the line and try to feel for a bulge. If you feel a bulge in the line, there may be a clog. If that is the case, you'll want to call your plumber for some additional help since the drain line will most likely need replaced.
Run Your Garbage Disposal
If you have a garbage disposal, it is actually connected to your dishwasher via the plumbing. If your garbage disposal is not working properly, it will be difficult for your dishwasher to drain properly. Make sure that your garbage disposal is working. If your garbage disposal is not working, fixing it may also fix your dishwasher.
Work your way through the suggestions above to see if you can fix the drainage problem yourself. If none of the steps above work, then give your plumber or appliance repair technician a call, and let them know what you have done to diagnose the plumbing problem. This information will make their jobs easier.