Honeywell Humidifier HCM-350 Series Manual

The Honeywell HCM-350 Series is a cool mist humidifier designed for medium to large rooms up to 500 sq. ft. It features a 3-speed quiet operation, a 1-gallon tank capacity, UV technology to kill up to 99.9% of bacteria, mold, and fungus in the water, an easy-to-clean design, a refill indicator light, and an auto-shutoff function. 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. Filling the Water Tank 7. Cleaning & Maintenance 8. UV Technology 9. Care & Storage 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Water Tank, Base Unit with UV Chamber, Control Panel, Mist Outlet, and Demineralization Cartridge (optional).

Feature	Description
UV Technology	UV light kills up to 99.9% of bacteria, mold, and fungus in water
3-Speed Settings	Low, Medium, and High for adjustable mist output
1-Gallon Tank Capacity	Provides up to 24 hours of operation on low setting
Quiet Operation	Designed for bedroom or office use
Refill Indicator Light	LED light turns on when tank is empty
Auto Shut-Off	Turns off automatically when tank is removed or empty
Easy-to-Clean Design	Wide tank opening and dishwasher-safe parts (top rack)
Demineralization Cartridge	Optional cartridge reduces white dust (mineral deposits)
Carry Handle	Integrated handle for easy tank transport
Adjustable Mist Nozzle	360-degree rotating nozzle directs mist where needed

Installation & Setup

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

Remove all packaging materials from the base unit and water tank.
Place the base unit on a flat, stable surface at least 4 inches away from walls and furniture.
Fill the water tank with clean, cool tap water (see Filling Instructions).
Insert the optional demineralization cartridge if desired (follow cartridge instructions).
Place the filled tank onto the base unit, ensuring it is seated properly.
Plug the power cord into a standard 120V AC outlet.

WARNING! Do not place on carpets or uneven surfaces. Keep away from heat sources and direct sunlight.

First-Time Use

Power on the humidifier; follow these initial steps.

Ensure the unit is unplugged. Fill the tank with clean, cool water.
Place the tank on the base and plug the unit into an electrical outlet.
Press the POWER button. The unit will beep and the UV indicator light will turn on.
Select your desired mist output speed (LOW, MEDIUM, HIGH) using the SPEED button.
Adjust the mist nozzle to direct the cool mist away from walls and furniture.
The humidifier will begin producing mist. Allow 15-20 minutes to notice humidity increase.

CAUTION! Use only clean, cool tap or distilled water. Do not add oils, fragrances, or chemicals to the water tank.

Specifications

Model Series: HCM-350 (Cool Moisture Humidifier).
Room Coverage: Up to 500 square feet (medium to large room).
Tank Capacity: 1 gallon (3.8 liters).
Run Time: Up to 24 hours on low setting.
Mist Output: Adjustable via 3-speed settings.
UV Technology: UV light kills bacteria, mold, and fungus in water.
Noise Level: Quiet operation, suitable for bedrooms.
Power Source: 120V AC, 60Hz.
Dimensions (approx.): 13.5" H x 10.5" W x 10.5" D.
Weight (empty): 5.5 lbs.

Controls and Operation

Control Panel: POWER Button, SPEED Button (cycles through Low, Medium, High), UV Indicator Light, Refill Indicator Light.

Operation: Press POWER to turn unit on/off. Press SPEED to select mist output. The UV light indicates the UV chamber is active. The Refill light illuminates when the water tank is empty.

Speed Settings: LOW for quiet, nighttime operation (up to 24 hrs). MEDIUM for average humidity needs (up to 18 hrs). HIGH for maximum mist output in dry conditions (up to 12 hrs).

Auto Shut-Off: The unit will automatically power off when the water tank is empty or removed. The refill light will remain on until the tank is refilled and replaced.

Filling the Water Tank

Always turn off and unplug the unit before filling.

Lift the water tank off the base unit using the carry handle.
Turn the tank upside down and unscrew the tank cap (located on the bottom).
Fill the tank with clean, cool tap water or distilled water. Do not overfill.
Screw the tank cap back on securely. Ensure the O-ring is in place and not damaged.
Turn the tank right-side up. Wipe any excess water from the exterior.
Place the tank back onto the base unit, aligning it properly until it clicks into place.

Tip: Using distilled or demineralized water can reduce white dust. The optional demineralization cartridge also helps.

Cleaning & Maintenance

Regular cleaning prevents mold and mineral buildup. Clean every 1-2 weeks during use.

Unplug the unit. Remove the water tank and empty any remaining water.
Clean the Tank: Wash the tank with mild dish soap and warm water. Use a soft brush if needed. Rinse thoroughly. The tank is dishwasher safe (top rack only).
Clean the Base: Wipe the base exterior with a damp cloth. Do not immerse in water.
Clean the UV Chamber & Mist Module: Remove the mist module (consult manual for release tabs). Rinse under warm water. Use a vinegar solution (1 part white vinegar to 2 parts water) to soak and remove mineral deposits for 20 minutes. Rinse thoroughly.
Dry Completely: Allow all parts to air dry completely before reassembling.
Demineralization Cartridge: Replace every 1-2 months or as indicated.

WARNING! Never use harsh chemicals, abrasives, or bleach. Do not operate the unit without all parts fully assembled and dry.

UV Technology

The UV light inside the base unit treats water as it passes through, killing up to 99.9% of bacteria, mold, and fungus. The UV indicator light on the control panel shows the UV system is active when the unit is powered on.

Note: The UV light is not user-serviceable. If the UV indicator light does not illuminate when the unit is on, contact customer service.

Care & Storage

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

Unplug the unit and empty all water from the tank and base.
Clean all parts thoroughly as described in the Cleaning section.
Allow all parts to dry completely for at least 24 hours.
Reassemble the unit and place it in its original box or a clean, dry place.
Store in a cool, dry location away from direct sunlight.

CAUTION! Never store the unit with water inside, as this can lead to mold growth and damage.

Regulatory Information

FCC Part 15: 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.honeywellpluggedin.com or contact 1-800-332-1110.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No mist output	Empty tank, incorrect assembly, low speed setting	Refill tank; ensure tank is seated properly; select a higher speed.
Unit not powering on	Not plugged in, power outlet issue	Check power cord connection; try a different outlet.
White dust on surfaces	Hard water minerals	Use distilled water; install/replace demineralization cartridge; clean more frequently.
Water leaking	Loose or damaged tank cap, overfilled tank	Ensure tank cap is tight and O-ring is intact; do not overfill the tank.
Unusual noise	Mineral buildup, low water level	Clean the mist module and base; refill the water tank.
UV light not on	UV system issue	Ensure unit is on; if light remains off, unit may require service.
Refill light stays on	Tank not seated, empty tank	Remove and reseat the tank; refill if empty.

Reset: Unplug the unit for 2 minutes, then plug back in.

Service: 1-800-332-1110; www.honeywellpluggedin.com