Honeywell Humidifier HDH-166 Manual

The Honeywell Humidifier HDH-166 is a cool mist humidifier designed to add comfortable moisture to dry air. It features a 1-gallon tank capacity, adjustable mist control, a quiet operation fan, an easy-to-fill tank, a wicking filter, an automatic shut-off when empty, and a night light function. Ideal for medium-sized rooms. Below are key sections for safety, features, installation, setup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Water Tank, Base Unit with Motor, Mist Nozzle, Control Knob, Filter, Night Light, Power Cord.

Installation & Setup

Unpack and inspect all contents. Place on a stable, level, waterproof surface.

1. Remove all packaging materials from the humidifier and tank.
2. Install the filter: Remove filter from package, soak in cool water for 15 minutes, then insert into filter compartment in base.
3. Fill the tank: Carry tank to sink, remove cap, fill with cool, clean water. Replace cap securely.
4. Place tank on base: Align tank with base and set down gently. Ensure it is seated properly.
5. Plug into a 120V AC electrical outlet.

WARNING! Use only clean, cool water. Do not use hot water or add essential oils, as this may damage the unit. Place on a moisture-resistant surface away from walls and furniture.

First-Time Use

After installation, prepare the unit for operation.

1. Ensure the humidifier is on a flat, stable surface.
2. Turn the Mist Control Knob to the desired setting (Low, Medium, High).
3. Adjust the 360° mist nozzle to direct mist away from walls and furniture.
4. To use the night light, press the Night Light button (if equipped).
5. The unit will begin producing mist. Allow a few minutes for mist to appear.

CAUTION! Never operate the humidifier without water in the tank or without the filter properly installed. Always use the unit in an upright position.

Specifications

• Model: HDH-166
• Tank Capacity: 1 Gallon (3.8 Liters)
• Run Time: Up to 24 hours (low setting)
• Room Coverage: Medium rooms up to 300 sq. ft.
• Mist Output: Adjustable, up to 1.5 gallons per day
• Operation: Cool Mist Ultrasonic (Quiet Fan)
• Filter Type: Wicking Demineralization Filter (HDH-166F)
• Power: 120V AC, 60Hz, 25W
• Dimensions (approx.): 11.5" H x 10.5" W x 7.5" D
• Weight (empty): 4.5 lbs

Controls and Operation

Primary controls are located on the front or top of the base unit.

Control Knob: Rotate to adjust mist output from Low (minimal mist) to High (maximum mist). Turning to "OFF" position powers down the fan.

Night Light Button: Press to turn the soft blue night light On or Off (model dependent).

Operation: When powered and with water, the fan will draw air through the moistened filter, creating a cool mist. The Automatic Shut-Off will activate when the water tank is empty, turning off the fan and night light.

Maintenance & Cleaning

Regular cleaning prevents mold and mineral buildup.

1. Daily: Empty any remaining water from the tank and base if not in use for more than a day.
2. Weekly Cleaning: Unplug unit. Disassemble tank and base. Clean all water-contact surfaces with a soft brush and a mixture of white vinegar and water (1:1 ratio) or a mild detergent. Rinse thoroughly with clean water.
3. Drying: Allow all parts to air dry completely before reassembly or storage.
4. Exterior: Wipe exterior with a soft, damp cloth. Do not immerse base in water.

WARNING! Never use abrasive cleaners, bleach, or harsh chemicals. Always unplug the unit before cleaning.

Filter Replacement

The wicking filter should be replaced every 1-2 months or as needed, depending on water hardness and usage.

1. Unplug the humidifier and remove the water tank.
2. Open the filter compartment on the base (usually a lid or cover).
3. Remove the old filter and discard it.
4. Soak the new filter (Model HDH-166F) in cool water for 15 minutes.
5. Insert the new, soaked filter into the compartment. Ensure it is seated flat.
6. Close the compartment and reassemble the unit.

Tip: Using distilled or demineralized water can extend filter life and reduce white dust.

Safety Features

Automatic Shut-Off: The fan and night light will automatically turn off when the water tank is empty, preventing damage to the motor.

Tip-Over Protection: Some models include a switch that turns the unit off if it is tipped over.

Water Leak Prevention: Tight-sealing tank cap and base design help prevent leaks when unit is upright.

Care & Storage

When not in use for an extended period (e.g., summer months), prepare the humidifier for storage.

1. Unplug the power cord.
2. Empty and thoroughly clean the tank and base as described in the cleaning section.
3. Remove and discard the old filter. Do not store the unit with a wet filter inside.
4. Allow all parts to dry completely.
5. Reassemble the unit and store in its original box or a clean, dry place.

CAUTION! Never store the humidifier with water in the tank, as this can lead to mold growth and damage.

Regulatory Information

This device complies with Part 15 of the FCC Rules. Operation is subject to the condition that this device does not cause harmful interference. Copyright © Honeywell International Inc. Honeywell and the Honeywell Humidifier design are trademarks of Honeywell International Inc. For support, visit www.honeywellhumidifiers.com or contact customer service at 1-800-332-1110.

Troubleshooting

Reset: Unplug unit for 5 minutes, then restart.

Service: For issues not resolved above, contact Honeywell Customer Service at 1-800-332-1110 or visit www.honeywellhumidifiers.com.