Front-loading washers can get water stuck in the door, leading to mold and mildew. The mold and mildew can give off a musty odor. Luckily, there are some things you can do to prevent the smell: Leave the door open after washing your clothes. Once your washer finishes cleaning your clothes, take out wet clothes as soon as possible. Make sure you’re using the proper amount of high-efficiency (HE) detergent.