Levoit LUH-A603-WUS Cool Mist Humidifier Manual featured img

Levoit LUH-A603-WUS Cool Mist Humidifier Manual

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Levoit LUH-A603-WUS Cool Mist Humidifier Manual

Levoit LUH-A603-WUS Cool Mist Humidifier Manual product img


Power SupplyAC 120V, 60Hz
Rated Power25W
Water Tank Capacity1.58 gal / 6 L


Max Run Time

Up to 60 hours on minimum mist setting

Note: The humidifier may run for a longer or shorter time depending on the environmental temperature and humidity.

Noise Level≤ 30dB
Effective Range215–505 ft² / 20–47 m²
Dimensions9.7 x 8.1 x 13.4 in /

24.5 x 20.5 x 34 cm

Weight4.2 lb / 1.9 kg

Package Contents

  • 1 × Ultrasonic Humidifier
  • 2 × Water Filter Sponge (1 Pre-Installed)
  • 1 × Cleaning Brush
  • 1 × User Manual


General Safety

  • Only use the humidifier as described in this manual.
  • Place the humidifier and cord so that it will not be knocked over. Do not place near large pieces of furniture or in high-traffic areas.
  • When not in use, turn the humidifier off and disconnect from power by removing the plug from the outlet.
  • Do not use the humidifier in wet environments.
  • Keep the humidifier out of reach of children.
  • Do not open the base or remove the water level sensor for self-servicing.
  • Always unplug your humidifier from the power outlet before cleaning your humidifier or detaching the water tank from the humidifier base.
  • Always make sure to place the humidifier on a flat, level surface before operation.
  • Only fill the water tank with clean water. Never fill the water tank with any other liquids.
  • Do not place the humidifier near sources of heat, such as stovetops, ovens, or radiators.
  • Do not place the humidifier directly on floors, carpets, or rugs.
  • Do not use other items as replacement parts for this product.
  • Do not cover the nozzle while the humidifier is on. Doing so may damage the humidifier.
  • Remove the water tank from the base before moving the humidifier.
  • Do not immerse the humidifier base, power cord, or plug in water.
  • If the humidifier is damaged or is not functioning properly, stop using it and contact Customer Support immediately

Power & Cord

  • Ensure that the plug fits properly into a polarized socket.
  • Do not handle the power cord or plug with wet hands. Keep the plug and power cord away from liquids.
  • Your humidifier has a polarized plug (one prong is wider than the other), which fits into a polarized outlet only one way. This is a safety feature to reduce the risk of electric shock. If the plug does not fit, reverse the plug. If it still does not fit, do not use the plugin that outlet. Do not bypass this safety feature.
  • If the power supply cord is damaged, it must be replaced by Arovast Corporation or similarly qualified persons in order to avoid an electric or fire hazard. Please contact Customer Support.
  • Unplugging the power cord will disable the remote control of the humidifier and temporarily disconnect the humidifier from VeSync and other third-party apps.

Electromagnetic Fields (EMF)
This humidifier complies with all standards regarding electromagnetic fields (EMF). If handled properly and according to the instructions in this user manual, the appliance is safe to use based on scientific evidence available today.


Levoit LUH-A603-WUS Cool Mist Humidifier Manual fig 1

  • A. Nozzle
  • B. Water Tank Cover
  • C. Dust Cover
  • D. Mist Tube
  • E. Water Tank
  • F. Base
  • G. Refill Indicator Light
  • H. Control Knob
  • I. Max Water Line (Tank)
  • J. Water Tank Handles
  • K. Water Filter
  • L. Power Cord
  • M. Float
  • N. Float Brackets
  • O. Max Water Line (Base)
  • P. Secondary Float
  • Q. Transducer
  • R. Air Outlet
  • S. Air Inlet
  • T. Feet
  • U. Water Outlet Valve Assembly
  • V. Water Outlet Valve
  • W. Noise Silencer
  • X. Cleaning Brush


Control Knob

  • Rotate clockwise to turn on the humidifier and adjust the mist level.
  • Rotate counterclockwise to turn off the humidifier.

Refill Indicator Light

  • The red light turns on when the water tank is empty. Refill the water tank.
  • The red light turns off when the water tank is filled.

There is a clicking sound when the humidifier turns on/off.


  1. Remove all packaging. Take the water tank off of the base and remove all tape.
  2. Clean the humidifier before first use.
    Note: Check to make sure that the water filter is correctly in place. If not, then rotate the filter clockwise to secure it in place. [Figure 1.1]
    Levoit LUH-A603-WUS Cool Mist Humidifier Manual fig 2
  3. Choose a hard, flat location for the humidifier at least 12 inches / 30 cm away from any walls. The surface must be water-resistant. [Figure 1.2]
  4. The mist should be directed away from walls, furniture, bedding, and appliances.
    Levoit LUH-A603-WUS Cool Mist Humidifier Manual fig 3

Filling & Refilling

  1. Remove the water tank cover. Use the handles to remove the tank from the base. Fill the tank with room-temperature water. [Figure 1.3].
    • We recommend using purified or distilled water to fill the tank.
    • Do not fill past the tank’s max water line.
    • Replace the water tank cover and place the tank back on the base. [Figure 1.4]
      Levoit LUH-A603-WUS Cool Mist Humidifier Manual fig 4Levoit LUH-A603-WUS Cool Mist Humidifier Manual fig 5


  1. Rotate the Control Knob clockwise to turn the humidifier on. Adjust the knob to your desired mist level.
  2. Rotate the nozzle to adjust the direction of the mist. [Figure 2.1]
  3. When your room has reached your preferred humidity level, turn the humidifier to a lower setting, or turn it off.
  4. Rotate the Control Knob counterclockwise to turn the humidifier off.

If there is no water in the tank or the tank is removed, the humidifier will stop misting and the Refill Indicator Light will turn on. Refill the tank and place it on the base.

Levoit LUH-A603-WUS Cool Mist Humidifier Manual fig 6

Important Tips
Your humidifier must have the correct level of water in the base chamber to work properly. If there is too much water in the base chamber, the humidifier cannot create mist.

  • Only add water to the water tank.
  • Avoid moving or shaking the humidifier.
  • Before moving the humidifier, turn it off, unplug it, and remove the water tank.
  • If your humidifier doesn’t produce mist correctly, check the max water line to see if there is too much water in the base chamber. Pour out extra water. [Figure 2.2]


  • All maintenance should be done on a water-resistant surface.
  • Change the water daily to avoid bacteria growth.
  • Use a tissue or cloth to clean the nozzle regularly.
  • If not using the humidifier for 3 days or longer, do not leave water inside.

You should clean your humidifier every 3 days, and when you’re ready to store it.


  • Never immerse the base in water or liquid. Do not place any part of the humidifier in a dishwasher.
  • Do not use detergents to clean the humidifier.
  1. Unplug the humidifier. Remove and rinse the water tank cover and dust cover. [Figure 3.1]
  2. Remove the water tank and pour out any water from the tank and base chamber.
    Note: When pouring out water, hold down the float to ensure that it does not fall out of the base chamber.
  3. Remove the water filter from the tank by rotating it counterclockwise. [Figure 3.2]
  4. Rinse the tank, water filter, and base chamber with room-temperature water.
    Levoit LUH-A603-WUS Cool Mist Humidifier Manual fig 7

Descaling Your Humidifier

  1. Remove the water filter from the tank by rotating it counterclockwise.
  2. Fill the tank with 3 US cups / 710 mL of distilled white vinegar.
  3. Replace the tank cover and swish the vinegar around the tank. [Figure 3.3]
  4. Place the tank on the base and soak for 15–20 minutes. Vinegar will drain into the base chamber and loosen the scale (mineral buildup). [Figure 3.4]
  5. Pour out any vinegar and flip the tank over. Remove the noise silencer by pressing the release tab and gently pulling it off. [Figure 3.5]
    Levoit LUH-A603-WUS Cool Mist Humidifier Manual fig 8
  6. Remove the float from the base chamber by pulling up the larger side of the float [Figure 3.6] and pulling the shaft out from the float brackets. One side of the brackets is open (U-shaped) to allow removal. [Figure 3.7]
    Levoit LUH-A603-WUS Cool Mist Humidifier Manual fig 9
  7. Place the float, water filter, and noise silencer in a container. Fill with enough vinegar to cover them. Soak for 15–20 minutes.
  8. Use a cleaning brush and a soft cloth to remove the scale from all parts.
  9. Rinse all parts until any vinegar smell is completely gone. 10. Completely dry all parts with a cloth before reassembling.
    Levoit LUH-A603-WUS Cool Mist Humidifier Manual fig 10

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:

  1. This device may not cause harmful interference, and
  2.  This device must accept any interference received, including interference that may cause undesired operation.

NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

  • Reorient or relocate the receiving antenna.
  • Increase the separation between the equipment and the receiver.
  • Connect the equipment to an outlet on a circuit different from that to which the receiver is connected.
  • Consult the dealer or an experienced radio/TV technician for help.

Conduct only the user maintenance found in this manual. Other maintenance and servicing can cause harmful interference and can void the required FCC compliance. The manufacturer is not responsible for any radio or TV interference caused by unauthorized modification to the equipment. It is the responsibility of the user to correct such interference.


ProblemPossible Solution



Little or no mist comes out.

Turn the mist level to a higher setting.
There may be too much water in the base chamber. Empty the base chamber. Refill the water tank (not the base chamber) and place the water tank properly onto the base.
Make sure the air inlet on the bottom of the base is not blocked. The humidifier should not be set on carpet or other surfaces that may block the air inlet.
Make sure the nozzle is not blocked or clogged.

Humidifier produces an unusual smell.

If the humidifier is new, unplug and rinse all parts, then place in a cool, dry place for 12 hours.
Clean the water tank and base chamber (see Care & Maintenance, page 6).
Condensation forms around humidifier or windows. 

Humidity may be too high. Turn down the mist level, turn off the humidifier, or open a door or window in the room.

Mold grows inside the humidifier.Clean the water tank and base chamber regularly (see Care & Maintenance, page 6).


Refill Indicator Light turns on.

Fill the water tank.
Place the water tank properly on the base.
Clean the water filter (see page 7) or replace it with a new one. To request a new water filter, contact Customer Support (see page 10).



Product NameLevoit VeSync Core™ 600S Smart True HEPA Air Purifier
For your own reference, we strongly recommend that you record your order ID and date of purchase.
Date of Purchase
Order ID


Terms & Policy
Arovast Corporation (“Arovast”) warrants this product to the original purchaser to be free from defects in material and workmanship, under normal use and conditions, for a period of 2 years from the date of original purchase. Arovast agrees, at our option during the warranty period, to repair any defect in material or workmanship or furnish an equal product in exchange without charge, subject to verification of the defect or malfunction and proof of the date of purchase.

There is no other express warranty. This warranty does not apply:
  • If the product has been modified from its original condition;
  • If the product has not been used in accordance with directions and instructions in the user manual;
  • To damages or defects caused by accident, abuse, misuse, or improper or inadequate maintenance;
  • To damages or defects caused by service or repair of the product performed by an unauthorized service provider or by anyone other than Arovast;
  • To damages or defects occurring during commercial use, rental use, or any use for which the product is not intended;
  • To damages or defects exceeding the cost of the product.

Arovast will not be liable for indirect, incidental, or consequential damages in connection with the use of the product covered by this warranty. This warranty extends only to the original consumer purchaser of the product and is not transferable to any subsequent owner of the product regardless of whether the product is transferred during the specified term of the warranty.

This warranty does not extend to products purchased from unauthorized sellers. Arovast’s warranty extends only to products purchased from authorized sellers that are subject to Arovast’s quality controls and have agreed to follow its quality controls. All implied warranties are limited to the period of this limited warranty. This warranty gives you specific legal rights and you may also have other rights which vary from state to state. Some states do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you.




Levoit LUH-A603-WUS Cool Mist Humidifier Manual

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