Inspection

• Look inside the washing machine to make sure there are no wet clothes lying in the washer. Also, look for visible signs of mold and mildew, such as discoloration in the washing machine tub. Try to remove any visible mold with a wet sponge or towel. Throw the sponge or towel away when you're done. Note the smell of the tub. Does it smell like mold as soon as the lid is opened? This may help you to diagnose when the problem is removed.
  
  

White Vinegar

• There are numerous methods of mold removal; however, sometimes the easiest are the best. Start by running a cycle of the washer with just 1/4 cup of white vinegar in hot water. Do not add clothing to the wash. This wash cycle will have a strong smell. Be sure to let the tub drain completely after this cycle.
  
  

Bleach

• If white vinegar does not work, or if you don't have any white vinegar on hand, try running a cycle of 1 cup of bleach in hot water. Again, make sure to run the load completely and without clothing in it.
  
  

The Smell Test

• At the end of the first empty load with either white vinegar or bleach, see if the smell of mold has left the drum. Run another empty load with white vinegar or bleach if necessary to remove the mold smell. Additionally, you may want to run another empty load with just plain water to remove the smell of white vinegar or bleach if that smell lingers. When you're done, there should be no smell in the tub of the washing machine.