For the past month, the laundry has smelled moldy/mildewy - you know how towels can smell if you wash them and then forget you washed them and they sit for a few days and well, I have done that before and yech... no matter what I did (run bleach only through with hot water, run vinegar only through with hot water, etc), it smelled. So I did some investigating and what I found out is that washing machines, especially front load washers, can get a buildup from detergent and softener mostly on the rubber gasket around the door. The buildup starts growing stuff and it imparts onto the laundry. the water that is left in the drum can also be infected. I found this stuff on Amazon and used it this week. What a difference! I ran it through twice and then did some laundry. Smell all gone, house smells good again when dryer is running. Based on reviews, I also changed detergent - link is below