Empty the dishwasher of any dishes, close the door, and then start it on the normal wash cycle. Do not add any dish detergent or rinse aids.
Open the door after two or three minutes after the bottom of the dishwasher fills with water.
Pour 1 to 2 cups of apple cider vinegar in with the water.
Close the door, and resume the dishwasher. If the hard water deposits or smell remain, repeat the process again, but this time use 3 cups of apple cider vinegar.
Soak paper towels with apple cider vinegar, and place them directly on top of stubborn hard water deposits inside your dishwasher. Leave them there for one hour, but check on them often to resoak and re-adhere the paper towels as necessary, especially for the sides and the top of the dishwasher. You can also use painter's tape, which easily comes off, to help keep the paper towels in place. After one hour, scrub the deposits off with the paper towels.