Levoit Humidifier OasisMist LUH-O451S-WEU Manual

The Levoit OasisMist LUH-O451S-WEU is a 4.5L ultrasonic cool mist humidifier designed for medium to large rooms. It features a 360° nozzle, three mist levels, a built-in essential oil diffuser tray, a night light with adjustable brightness, a 1-12 hour timer, auto shut-off when water runs low, and a quiet operation mode. Below are key sections for safety, features, installation, setup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 4.5L Water Tank, 360° Adjustable Nozzle, Control Panel, Essential Oil Tray, Night Light, Ultrasonic Mist Generator.

Feature	Description
Water Tank Capacity	4.5 Liters
Mist Output	Up to 300 mL/h
Mist Levels	Low, Medium, High
Run Time	Up to 40 hours on low setting
Timer	1 to 12 hours
Night Light	Adjustable brightness (High/Low/Off)
Essential Oil Diffuser	Built-in tray for aromatherapy
Auto Shut-Off	Activates when water tank is empty
Noise Level	< 30 dB in Quiet Sleep Mode
Power	24V DC, 0.6A (AC Adapter included)

Installation & Setup

Unpack and inspect all contents. Place on a stable, flat, and level surface away from direct sunlight and electronics.

1. Remove the water tank from the base.
2. Fill the tank with clean, cool tap or distilled water up to the MAX line. Do not overfill.
3. Securely reattach the tank to the base, ensuring it is properly seated.
4. Plug the DC power adapter into the humidifier's power port, then plug the adapter into a standard 220-240V AC wall outlet.

WARNING! Do not use the humidifier without water. Always place on a water-resistant surface. Keep out of reach of children.

First-Time Use

Power on the humidifier; the indicator light will illuminate.

1. Press the POWER button to turn on the unit.
2. Press the MIST button to cycle through Low, Medium, and High mist output levels.
3. Adjust the 360° nozzle to direct mist away from walls, furniture, and electronics.
4. Press the TIMER button to set a shut-off duration (1-12 hours).
5. Press the LIGHT button to adjust night light brightness (High/Low/Off).

CAUTION! Use only the provided power adapter. Never add water through the mist outlet. Ensure the tank cap is tightly closed.

Specifications

• Model: LUH-O451S-WEU
• Tank Capacity: 4.5 Liters
• Room Coverage: Up to 40 m² (430 sq ft)
• Mist Output: 300 mL/h Max
• Operating Time: 12-40 hours (depending on mist level)
• Noise Level: < 30 dB (Sleep Mode)
• Power Input: 24V DC, 0.6A
• Adapter Input: 100-240V AC, 50/60Hz
• Product Dimensions: 26.5 x 26.5 x 34.5 cm
• Weight: 2.1 kg (with empty tank)

Controls and Settings

Access all functions via the capacitive touch control panel on the top of the unit.

Control Panel: POWER, MIST (Level), TIMER, LIGHT (Night Light).

POWER: Turns the humidifier on/off. A short beep confirms press.
MIST: Cycles through mist levels: Low (LED 1) -> Medium (LED 2) -> High (LED 3).
TIMER: Sets auto-off timer. Each press increases time by 1 hour (1-12 hrs), then cycles back to continuous operation.
LIGHT: Controls the night light: High Brightness -> Low Brightness -> Off.
Indicator Lights: Red light indicates low water level. Blue/White lights indicate normal operation and settings.

Operation Modes

Normal Mode: Operates at selected mist level (Low/Med/High).
Sleep Mode: Automatically activates when the timer is set. The display lights dim after 30 seconds of inactivity, and mist output is optimized for quiet operation.
Auto Mode: The humidifier maintains a comfortable humidity level by automatically adjusting mist output (if equipped with a humidistat - check model specifics).

1. For continuous operation, do not set the timer.
2. For nighttime use, set the timer and use the low mist level and dimmed night light.
3. Always use clean, cool water for optimal performance and to minimize white dust.

Tip: Using distilled water can significantly reduce mineral buildup and white dust.

Using the Essential Oil Diffuser

The built-in aroma box allows for gentle aromatherapy.

1. Ensure the humidifier is turned OFF and unplugged.
2. Pull out the essential oil tray located on the side or top of the unit.
3. Add 3-5 drops of your preferred pure essential oil onto the cotton pad inside the tray. Do not pour oil directly into the water tank.
4. Slide the tray back into its slot securely.
5. Turn on the humidifier as normal. The mist will carry the aroma into the air.

WARNING! Use only 100% pure, water-soluble essential oils. Do not use fragrance oils, chemicals, or thick oils. Clean the tray regularly to prevent clogging.

Care, Cleaning & Maintenance

Regular cleaning prevents mold, bacteria, and mineral scale buildup.

Daily: Empty and rinse the water tank with fresh water if not in use for more than a day.
Weekly Cleaning:

1. Unplug the unit. Remove the water tank and empty any remaining water.
2. Fill the tank with 2-3 cups of clean water and add 1 teaspoon of white vinegar or a manufacturer-recommended cleaner.
3. Swirl the solution inside the tank, then use a soft brush to clean the interior and the tank opening. Let it sit for 15-20 minutes.
4. Rinse thoroughly 2-3 times with clean water to remove all cleaning solution residue.
5. Wipe the exterior and base with a damp, soft cloth. Never immerse the base in water.
6. Allow all parts to air dry completely before reassembling.

Descaling (Monthly): For areas with hard water, use a dedicated descaling solution or a stronger vinegar/water mix (1:1) to remove mineral deposits from the ultrasonic disc (metal plate at the bottom of the base). Gently wipe with a soft cloth.

CAUTION! Always unplug before cleaning. Do not use abrasive cleaners, detergents, or submerge the base unit in water. Ensure all parts are completely dry before use.

Regulatory Information

CE Certified: Complies with European health, safety, and environmental protection standards. This device complies with relevant EU directives. Waste Electrical and Electronic Equipment (WEEE): Do not dispose of with household waste. Use designated collection facilities. For support within the EU, visit www.levoit.com/eu or contact the local retailer. Copyright and design rights are property of Levoit.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No mist output	Empty tank / Incorrect assembly	Fill tank with water. Ensure tank is correctly seated on the base. Check that the cap is tight.
Red indicator light is on	Low water level	Refill the water tank. The unit will auto shut-off when empty.
White dust around humidifier	Minerals in hard water	Use distilled or demineralized water. Clean the ultrasonic disc.
Unit not turning on	No power / Adapter issue	Ensure the unit is plugged in. Check the power adapter connection. Try a different outlet.
Water leakage	Overfilled tank / Loose cap / Crack	Do not fill above MAX line. Tighten the tank cap. Inspect tank and base for cracks.
Unusual noise	Vibration / Low water	Place on a perfectly flat surface. Ensure water level is sufficient.
Weak mist	Mineral buildup / Low mist setting	Clean the ultrasonic disc and water tank. Select a higher mist level.

Reset: Unplug the unit for 2 minutes, then plug it back in to reset the electronic controls.

Service: For EU support, visit www.levoit.com/eu or contact your point of purchase. Do not attempt to repair the unit yourself.