First, check to make sure you’re not doing anything to cause the dishwasher to malfunction. Review the manufacturer’s recommendations on how to use and maintain your dishwasher. Are you overloading your machine? Could a utensil be restricting the spinning motion of the spray arms? Do you load plates in the machine without scraping food off of them first?
After you check to ensure you’re following the manufacturer’s recommendations, you can then check for problems with the machine itself. Check for any grease, debris, or blockages in the strain screen and door gasket. The culprit could also be your spray arms, so try to spin the bottom and top arms with your hand to make sure they spin easily. If neither do or if they’re covered in dirt or food debris, you may need to clean them. To do so, remove the arms and gently clean them with a toothbrush and a pipe-cleaner. Once replaced, try running a clean cycle to see if your dishes fare any better.
If your dishes come out covered in water spots, the water from the dishwasher may be staying on your dishes too long. A simple rinse aid may help to solve this problem. If your glasses and plates come out with a white residue on them, you may have hard water. Try using a water softener or a detergent that helps to soften your water.
Your dishwasher leaks onto the floor
First, check your dishwasher door and door gasket. Look for any cracks, damage, or large debris that could be preventing the door from sealing completely. Try cleaning your door gasket with a disinfectant, and if you see any large cracks, you will likely need to replace the gasket.
The float switch — the mechanism that indicates your dishwasher’s water level — may be stuck in the down position, This can cause your machine to overfill and leak onto the floor. If your float switch is stuck, clean it and remove any plastic, string, or anything else that might be preventing it from functioning properly.
Your dishwasher doesn’t dry your dishes
This is often a problem with the dishwasher’s heating element. If your heating element is in working order, check the high-limit thermostat (a device that prevents the dishwasher from getting too hot). A malfunctioning high-limit thermostat can cause the heat to shut off before your dishes are fully dry. You can usually find your high limit thermostat at the bottom of the dishwasher tub, directly behind the access panel. You can use a multimeter to check the device. Lastly, check your rinse aid dispenser to make sure it’s not empty and that it’s dispensing properly. Without rinse aid, your dishes will not dry as easily.
Your dishwasher smells bad
Old, wet food is likely the cause of any bad smell coming from your dishwasher. Look through your machine carefully for any food, and clean your dishwasher’s screen (located at the bottom of your machine).
If your dishwasher has a chemical smell, a plastic plate or Tupperware container may have fallen down and melted onto the heating element. That said, it’s a good idea to load your dishwasher carefully and scrape your dishes to avoid unwanted odors.
Your dishwasher doesn’t start
Check the power sources to make sure you haven’t blown a fuse and ensure the outlet isn’t malfunctioning. You can even try power cycling the dishwasher.
Your dishwasher door may also be the problem. If it isn’t latched closed, for instance, it may not allow your dishwasher to start. That said, check for any problems with the latch before continuing.
If it sounds like your dishwasher is trying to work, but it just won’t run correctly, your motor may be stuck. If so, try spinning the fan motor by hand to see if that gets it moving. It’s important that you turn off the power using the main panel first, however, to avoid electrical shock.
Your dishwasher isn’t draining properly
This problem is obvious because your dishwasher floods the floor with water when you try to open it. First, try running your dishwasher a second time. A dishwasher that was unexpectedly turned off (say, by a brief power outage) could still have water inside because the cycle wasn’t complete. Simply running the cycle again can fix this problem.