How to Minimize Mold in Your Washing Machine – ConsumerReports.org

4. Leave the Door Open
Keep it ajar or wide open between loads to allow moisture to escape. If young children are present, lock the door to your laundry room. (CR shows you how to keep young kids safe from a front-load washer accident.)

5. Mind the Detergent Drawer
Remove it and clean on a routine basis. Rinse the drawer with water, wipe away the soap buildup, then let it dry. Between loads, wipe it dry or leave the drawer open so that it can air out.

6. Run a Tub-Clean Cycle Regularly
The recommended frequency varies—some brands say monthly or every 50 wash loads. If your washer doesn’t have this feature, Beguesse suggests running the sanitary cycle or simply a hot-water cycle and using a washer cleaner with bleach, such as Tide Washing Machine Cleaner, monthly. 

7. Ensure That the Machine is Level
Wash water will not drain properly if your washer isn’t perfectly level, so check it every so often. If you need to make adjustments, extend one foot at a time and check front-to-back and side-to-side with a level before tightening the lock nuts on the feet. 

8. Check the Drain Hose 
It shouldn’t be too long and should be inserted only 6 to 8 inches into your home’s drain pipe. More than that, and it can siphon foul-smelling water back into the washer, where it can sit.