Levoit Humidifier LUH-A251-WUS Manual

The Levoit LUH-A251-WUS is a 2.5L ultrasonic cool mist humidifier designed for medium to large rooms. It features a 360° nozzle, adjustable mist output, night light with auto-off, low water indicator, and whisper-quiet operation. Below are key sections for safety, features, setup, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation & Setup 3. First-Time Use 4. Specifications 5. Controls and Operation 6. Maintenance & Cleaning 7. Safety Precautions 8. Care & Storage 9. Regulatory Information 10. Troubleshooting

Features at a Glance

Key components: 2.5L water tank, ultrasonic mist generator, 360° adjustable nozzle, control panel, night light, and power adapter.

Feature	Description
2.5L Water Tank	Large capacity for up to 25 hours of continuous use
Ultrasonic Technology	Produces fine cool mist without heating water
360° Nozzle	Adjustable direction for targeted mist output
Adjustable Mist Output	Three levels: Low, Medium, High
Night Light	Soft blue light with auto-off option
Whisper-Quiet Operation	Quiet operation ideal for bedrooms and offices
Low Water Indicator	LED light alerts when water level is low
Auto Shut-Off	Turns off automatically when water tank is empty
Easy-Fill Design	Wide opening for convenient refilling
Filter-Free Operation	No replacement filters required

Installation & Setup

Unpack and inspect all components. Place on a flat, stable surface away from walls and electronics.

Remove all packaging materials from the humidifier and water tank.
Separate the water tank from the base unit by twisting counterclockwise.
Fill the tank with clean, cool tap water (do not exceed MAX line).
Reattach the tank to the base by aligning and twisting clockwise until secure.
Place the humidifier on a level surface at least 12 inches from walls.
Plug the power adapter into the humidifier and then into a standard 120V AC outlet.

WARNING! Do not place on carpets or uneven surfaces. Ensure the unit is upright before operation.

First-Time Use

Power on the humidifier and configure initial settings.

Press the POWER button to turn on the unit.
Adjust mist output using the MIST button to cycle through Low, Medium, and High settings.
Rotate the 360° nozzle to direct mist away from walls and furniture.
Press the NIGHT LIGHT button to turn the light on/off or enable auto-off mode.
Monitor the low water indicator; refill when LED turns red.

CAUTION! Use only clean, cool water. Do not add essential oils or other additives directly to the water tank.

Specifications

Model: LUH-A251-WUS
Tank Capacity: 2.5 liters (0.66 gallons)
Room Coverage: Up to 250 sq ft
Run Time: Up to 25 hours on Low setting
Mist Output: Adjustable: 100mL/h (Low), 200mL/h (Medium), 300mL/h (High)
Noise Level: <28 dB
Power Consumption: 25W
Power Source: 120V AC, 60Hz
Dimensions: 9.8" x 7.5" x 10.2"
Weight: 3.3 lbs (empty)

Controls and Operation

Control Panel: POWER button, MIST button, NIGHT LIGHT button.

Operation: Press POWER to turn on/off. Press MIST to cycle through output levels (Low → Medium → High). Press and hold MIST for 3 seconds to enter constant humidity mode. Press NIGHT LIGHT to toggle light modes (On → Auto-Off → Off).

Indicator Lights: Blue (normal operation), Red (low water), Flashing Red (empty tank/auto shut-off activated).

Maintenance & Cleaning

Regular cleaning prevents mineral buildup and ensures optimal performance.

Unplug the humidifier and remove the water tank.
Empty any remaining water from the tank and base.
Clean the tank with a mixture of white vinegar and water (1:1 ratio).
Use a soft brush to clean the ultrasonic disc at the bottom of the base.
Rinse all parts thoroughly with clean water.
Allow all components to air dry completely before reassembly.
For deep cleaning, use a solution of 2 teaspoons of bleach per gallon of water monthly.

Tip: Clean the humidifier at least once a week during regular use.

Safety Precautions

Important safety guidelines for proper operation.

Always unplug the unit before cleaning or maintenance.
Use only clean, cool tap water. Do not use hot water.
Do not add essential oils, medications, or fragrances to the water tank.
Keep out of reach of children and pets.
Do not operate the humidifier without water in the tank.
Place on a waterproof surface to prevent water damage.
Do not cover the mist outlet or air vents during operation.
If the power cord is damaged, discontinue use immediately.

Care & Storage

Proper care extends the life of your humidifier.

When not in use for extended periods, empty and dry all components completely.
Store in original packaging or a clean, dry place.
Do not store with water in the tank to prevent mold growth.
Inspect the unit before seasonal use for any damage or wear.

CAUTION! Never store the humidifier while wet. Ensure complete dryness to prevent bacterial growth.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits for residential use. Copyright © 2023 Levoit; trademarks of Vesync Co., Ltd. ETL listed for safety standards. For support, visit www.levoit.com or contact 1-888-726-8520.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No mist output	Empty water tank	Refill tank with clean water
Low mist output	Mineral buildup	Clean ultrasonic disc with vinegar solution
Unit not turning on	Power connection	Check power outlet and cord connection
Water leakage	Tank not properly seated	Remove and reattach tank securely
White dust around unit	Hard water minerals	Use distilled water or demineralization cartridge
Unusual noise	Vibrating surface	Place on level, solid surface
Night light not working	LED failure	Contact customer support for repair

Reset: Unplug for 5 minutes, then restart.

Service: 1-888-726-8520; www.levoit.com