Levoit Humidifier OasisMist LUH-O451S-WUS Manual

The Levoit OasisMist LUH-O451S-WUS is a 4.5L ultrasonic cool mist humidifier designed for medium to large rooms. It features a 360° nozzle, three mist levels, optional night light, auto mode with built-in humidity sensor, timer settings (1-12 hours), essential oil tray, and quiet operation. Below are key sections for safety, features, installation, setup, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation & Setup 3. First-Time Use 4. Specifications 5. Controls & Operation 6. Using Essential Oils 7. Maintenance & Cleaning 8. Smart Features 9. Care & Storage 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: 4.5L water tank, 360° adjustable mist nozzle, control panel with digital display, essential oil tray, built-in humidity sensor, night light.

Feature	Description
Water Tank Capacity	4.5 liters (1.2 gallons)
Mist Output	Up to 300 mL/h
Mist Levels	Low, Medium, High (adjustable)
Nozzle	360° rotatable for directional mist
Operation Modes	Manual, Auto (humidity-sensing), Sleep
Timer	1 to 12 hours
Night Light	Optional soft blue light, on/off control
Essential Oil Tray	For adding aromatherapy oils
Display	Digital display showing humidity, settings
Power	120V AC, 60Hz, 24W

Installation & Setup

Unpack and inspect contents. Place on a flat, stable, elevated surface away from walls and electronics.

Remove all packaging materials from tank and base.
Fill the water tank: Carry tank to sink, remove cap, fill with cool tap water (do not exceed MAX line).
Reattach tank to base: Ensure tank is securely seated and aligned.
Plug into a grounded 120V AC outlet.

WARNING! Use only clean, cool tap water. Do not use hot water or add oils directly to water tank. Keep away from children and pets.

First-Time Use

Power on humidifier; follow initial setup.

Press POWER button to turn on; default is Manual mode, Medium mist.
Set desired humidity: In Auto mode, use +/- buttons to set target humidity (40%-80% RH).
Adjust mist level: Press MIST button to cycle Low, Medium, High.
Set timer: Press TIMER, then +/- to set 1-12 hours; unit will auto shut off.
Night light: Press LIGHT button to turn on/off.

CAUTION! Place on a water-resistant surface. Do not move unit while operating or with water in tank.

Specifications

Model: LUH-O451S-WUS (OasisMist)
Tank Capacity: 4.5L (1.2 gal)
Room Coverage: Up to 500 sq ft
Mist Output: 300 mL/h max
Run Time: Up to 40 hours on Low setting
Noise Level: ≤ 30 dB (Sleep mode)
Humidity Sensor: Built-in, adjustable 40-80% RH
Display: Digital LED (humidity %, settings, indicators)
Power: 120V AC, 60Hz, 24W
Dimensions: 11.8" x 7.9" x 10.2"
Weight: 4.6 lbs (empty)

Controls & Operation

Control Panel: POWER, MIST (level), MODE (Manual/Auto/Sleep), TIMER, HUMIDITY (+/-), LIGHT.

Operation Modes: Manual (set mist level directly), Auto (maintains set humidity), Sleep (display off, quiet operation).

Timer: Set 1-12 hours for automatic shut-off. Night Light: Soft blue light, independent control. 360° Nozzle: Rotate to direct mist away from walls/furniture.

Using Essential Oils

Use only with provided essential oil tray.

Ensure humidifier is off and unplugged.
Pull out essential oil tray (located near nozzle).
Add 3-5 drops of pure essential oil onto cotton pad in tray.
Reinsert tray securely.
Operate as normal; mist will carry aroma.

WARNING: Never add oils directly to water tank or base—can damage unit and void warranty. Use only water-soluble, pure essential oils.

Maintenance & Cleaning

Regular cleaning prevents mold and mineral buildup.

Daily: Empty and refill tank with fresh water if not used for >24 hours.
Weekly: Clean tank and base with mild soap and water; rinse thoroughly.
Monthly: Descale with white vinegar solution (1 cup vinegar + 1 gallon water). Soak tank and base for 20 mins, scrub, rinse.
Filter: This model is filter-free; no replacement needed.

CAUTION! Unplug before cleaning. Do not immerse base in water. Dry all parts completely before reassembly.

Smart Features

Auto Mode: Built-in sensor monitors room humidity and adjusts mist output to maintain set level. Sleep Mode: Turns off display, operates at lowest noise. Timer: Program shut-off from 1 to 12 hours. Memory Function: Remembers last settings when powered back on.

Care & Storage

When not in use for extended periods:

Unplug unit.
Empty and thoroughly clean tank and base.
Allow all parts to air dry completely.
Store in original box in a cool, dry place.

Tip: Do not store with water in tank to prevent mold or mildew.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits for residential use. UL Listed: Meets safety standards. Copyright © 2023 Levoit. For support, visit www.levoit.com or contact 1-888-726-8520.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No mist output	Empty tank, low water	Refill tank with water; ensure tank is seated properly.
Weak mist	Mineral buildup, low setting	Clean unit with vinegar; increase mist level.
Water leakage	Tank not sealed, overfilled	Check tank cap and seal; do not exceed MAX line.
Unusual noise	Vibration, debris in fan	Place on flat surface; check for obstructions.
Display not working	Power issue, unplugged	Ensure unit is plugged in; press POWER button.
Auto mode not accurate	Sensor blocked, placement	Keep unit away from direct mist, vents; relocate.

Reset: Unplug for 60 seconds, then restart. If issues persist, contact support.

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