Replace a tank cap water valve Kaz model V3100

Best option might be to drop an email to the supplier of the humidifier Kaz at [email protected]

You can download the manual from this site in case it is any help.
http://s3.amazonaws.com/szmanuals/8a7c1db00996618dffc2e2382335c08c

This is a POSSIBLE answer: I found the manual at the Vicks site, read through it, but it did not mention replacement parts at all. However, at the very end of the manual was this paragraph, which might serve as a way for you to get what you need. Quoting the manual:

If you have any questions or comments, call the Kaz Consumer Service Department at 1-800-VAPOR-1-2 or, e-mail [email protected] or, write to Kaz, Consumer Service
Department, P.O. Box 544, Hudson, NY 12534, explaining just how the product is operating. Specify model number. Our Consumer Service Representative will advise you how to correct the problem yourself, or will ask you to return the product for repair or replacement.

here is link to the product manual:
http://www.kaz.com/kaz/store/product/ee12255399410005f09196a5b95a04bd/

the water tray goes in the bottom part with the vents in the back and the wick just stands upright inside resting against the brace on the tray and in front of the vents.

go to kaz.com and search using model # (usually found on the bottom of the humidifier)

go to kaz.com and search using your model # (found on the bottom of the unit usually). i had to do this a few months ago.

you can check at any local hardware store in your area. or you if your in canada you can check canadian tire. if nobody has them locally you might have to call the manufacturer of the product.

Check if the cap has a gasket or o-ring and is not worn. There are two designs for this model. The older model has the fill cap and valve together. The new design the fill cap and valve are at different locations. The new design has no hole in the bottom of the unit.
You can fixed the problem using a 1-1/2 inch washer for brass tubular found in the plumbing isles in HD or L. The rubber washer is 1 or 2 mm smaller then the grooves in the fill/valve cap. You can stretch the washer and it will fit perfectly in the grooves. When putting the fill/valve cap back with the washer, it will be tighter then before. Firmly turn and you should not have any leaks and make sure unit is level. You can plug the hole because the new design does not have a hole in the bottom of the unit.

http://www.kaz.com/kaz/support/manual/?ProductManualAction=renderProductManualById&ProductManualId=285ef863f85db2982e6f095560687917

Try to just fill the tank with water and set it upright on a table. If it leaks, the tank is cracked and needs to be replaced. Order one at kaz.com (search using model#). I have had this tank leak if the special cap is not sitting properly on the base. Make sure that the steam tower is properly locked in place before you place the water tank in the reservoir. The cap on the tank has a spring release that has to be correctly lined up so it only releases water when the water level in the reservoir drops.

http://homeappliance.manualsonline.com/manuals/mfg/vicks/v3100.html

This is the link to your manual.
Daily Maintenance
1. Turn switch to OFF position and unplug the cord from wall outlet.
2. Lift the Water Tank from Base. Carefully remove the Water Tray from the base being
careful not to damage the delicate Wicking Filter. Empty excess water from the Water Tray
without removing the Wicking Filter. Remove the Tank Cap and drain any water from the
Water Tank. Rinse the Water Tank with lukewarm water after each use. Wipe accessible
surfaces of the Water Tank and Water Tray clean with a soft, damp cloth.
3. Do not immerse the Base in water. For storage, wipe dry with a soft, clean cloth. Keep
water away from the Air Outlet.
4. Do not leave water in the Water Tank or Water Tray when unit is not in use as it may
result in the build up of mineral deposits and bacteria that can inhibit the output
efficiency of the humidifier. Please note that if water remains in the Water Tank for more
than a day or two, bacterial growth is possible.
5. Replace Water Tray with Wicking Filter. Then replace the Tank. Humidifier is now ready for
use.
Weekly Maintenance
Removing Scale
1. Remove the Water Tank and empty any remaining water from the Water Tank.
2. Turn switch to the ON position, either low or high speed, and operate Humidifier until the
Wicking Filter is thoroughly dry.
3. Turn switch to the OFF position and unplug the cord from wall outlet.
4. Remove Wicking Filter from the Water Tray by carefully lifting straight up taking care not to
tear filter.
5. Remove the Water Tray from the Base. Fill Water Tray with undiluted white vinegar. Let
stand for 20 minutes.
6. Dampen soft, clean cloth or sponge with undiluted white vinegar and wipe out Water Tray
to remove scale. Do not use soap, detergents or abrasive cleaners.
7. Rinse the Water Tray thoroughly in clean warm water or put in top shelf of dishwasher to
remove scale and vinegar before disinfecting the Water Tray.

Disinfecting the Water Tray and Tank
1. Fill tank with 1 teaspoon of household bleach in 1 gallon of water. Let stand twenty (20)
minutes, shaking vigorously every few minutes, drain and rinse with clean water until the
bleach smell is gone. Dry with a clean cloth or paper towel.
2. Wipe the Water Tray with a soft cloth dampened in the bleach and water solution. Rinse
the Water Tray thoroughly or place in dishwasher before proceeding.
3. Wipe all exterior surfaces of the Base with a soft, dry cloth. Do not immerse the Base in
water or use water to clean the base. An electric shock may result or the humidifier may
be damaged.

Hope this helps.
Good Luck.