Cleaning out your water cooler every time you change the bottle will prevent mold and other pathogens from growing in the wet environment. Some companies suggest using bleach, but there is a more natural, safer way to to this. Vinegar is cheap, and if there is any residue of it inside the cooler, it will not harm you or your family when you drink the water.
Unplug the water cooler and remove the old, empty bottle. Wait until the bottle is empty before cleaning out the unit.
Add the water and vinegar to the bucket. You can also use a combination of 3 quarts of water and 1 quart of vinegar.
Pour the vinegar into the reservoir of the water cooler.
Let the vinegar sit for 10 to 15 minutes.
Hold the bucket under both of the cold and hot taps on the water cooler.
Drain all of the vinegar out of the taps into the bucket. Discard the vinegar when finished.
Pour water into the reservoir and repeat steps 5 and 6 with the water several times until the water no longer smells like vinegar.