Heating element always on

Hi, I have a KitchenAid kudm24sewwh4 dishwasher. Today I noticed it was very hot I could feel and smell it. When I opened the door the heat about knocked me over. I left the door open and it cooled down. When I shut the door and check a couple min later it is getting hot again. If I leave the door cracked no problem but if I close the door the heating element comes on and stays on. I have reset the breaker and checked for loose wires. Any ideas?

Thanlks