There is a super loud humming from pipes when the dishwasher is used. It usually lasts for 20-40 seconds, and sometimes I can stop it by turning on the kitchen sink water, but not always. The dish washer seems to work fine, but I can't figure out the noise. It's terribly loud! Like a tuba! Thoughts?

Sounds like you have some sort of water hammer. You might try posting this in the plumbing board, I don't think this is any fault of the dishwasher, but rather the plumbing connection to it.