Honeywell Humidifier HEV355 Manual

The Honeywell HEV355 is a 3.5-gallon ultrasonic cool mist humidifier designed for medium to large rooms up to 500 sq ft. It features ultrasonic technology for quiet operation, adjustable mist output control, a built-in humidistat with auto shut-off, a night light with on/off option, a removable 3.5-gallon tank for easy filling, a wicking filter, and a top-fill design. 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 Settings 6. Operation Modes 7. Maintenance & Cleaning 8. Filter Replacement 9. Safety Features 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: 3.5-gallon water tank, ultrasonic mist generator, control panel with dial, humidistat, night light, filter compartment, and power base.

Feature	Description
Ultrasonic Technology	Produces visible cool mist quietly
Adjustable Mist Control	Dial to control mist output level
Built-in Humidistat	Automatically maintains desired humidity level
Auto Shut-Off	Turns off when desired humidity is reached or tank is empty
Night Light	Soft blue light with independent on/off switch
Top-Fill Design	Easy filling without removing tank
Removable Tank	3.5-gallon capacity for less frequent refills
Wicking Filter	Helps reduce white dust and minerals
Mist Outlet	Directional nozzle to aim mist flow
Power Indicator	LED shows when unit is powered

Installation & Setup

Unpack and inspect all parts. Place on a flat, level surface away from walls and electronics.

Remove tank: Lift tank off base and remove cap.
Fill with water: Use clean, cool tap water. Do not use hot water or additives.
Replace cap: Ensure cap is tightly sealed.
Position tank: Place tank back on base, aligning properly.
Install filter: Insert wicking filter into compartment if not pre-installed.
Plug into outlet: Use 120V AC power outlet.

WARNING! Place on a water-resistant surface. Keep away from children. Do not block mist outlet.

First-Time Use

Power on humidifier; set desired humidity and mist level.

Fill tank completely with clean, cool water.
Set humidistat: Turn dial to desired humidity level (40-60% recommended).
Adjust mist output: Use control dial to set mist intensity.
Turn on night light: Press night light button if desired.
Monitor operation: Mist should appear within 1-2 minutes.

CAUTION! Use only clean water. Never operate without water in tank.

Specifications

Tank Capacity: 3.5 gallons (13.2 liters).
Coverage Area: Up to 500 square feet.
Run Time: Up to 24 hours on low setting.
Technology: Ultrasonic cool mist.
Humidistat: Adjustable with auto shut-off.
Mist Output: Adjustable up to 1.5 gallons per day.
Night Light: Blue LED with on/off control.
Filter Type: Demineralization/wicking filter (replace every 1-2 months).
Power Source: 120V AC, 60Hz.
Dimensions: 13.5" H x 10.5" W x 9" D.

Controls and Settings

Control Panel: Power/mist control dial, humidistat dial, night light button, indicator lights.

Mist Control Dial: Turn clockwise to increase mist output, counterclockwise to decrease.

Humidistat Dial: Set desired humidity level (30-90% RH). Unit will auto shut-off when reached.

Night Light: Press button to turn blue light on/off independently.

Indicator Lights: Power LED (green), low water indicator (red) when tank is empty.

Operation Modes

Manual Mode: Adjust mist output manually with control dial.

Set humidistat to desired level.
Adjust mist output as needed for room conditions.
Unit runs continuously until tank is empty or humidity level is reached.

Auto Mode: Set humidistat; unit adjusts mist output automatically to maintain set humidity.

Night Mode: Use night light for low-light conditions; reduce mist output for quieter operation.

Tip: For best results, place humidifier at least 12 inches from walls and furniture.

Maintenance & Cleaning

Regular cleaning prevents mold and mineral buildup.

Unplug unit before cleaning.
Empty tank completely.
Clean tank: Use mild detergent and soft brush; rinse thoroughly.
Clean base: Wipe with damp cloth; do not immerse in water.
Descale: Use white vinegar solution for mineral deposits (1 part vinegar to 2 parts water).
Dry completely before reassembly.

CAUTION! Never use abrasive cleaners or submerge base in water.

Filter Replacement

Replace demineralization filter every 1-2 months or as needed.

Turn off and unplug humidifier.
Remove tank from base.
Access filter compartment on base.
Remove old filter and discard.
Insert new filter (HEV355F filter).
Reassemble and run for 5 minutes to prime filter.

Note: Using filter reduces white dust. Without filter, use distilled water.

Safety Features

Auto Shut-Off: Turns off when tank is empty or desired humidity is reached. Low Water Indicator: Red light alerts when tank needs refilling. Tip-Over Protection: Unit shuts off if tipped over.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits. UL Listed: Meets safety standards. Copyright © Honeywell International Inc. For support, visit www.honeywellhumidifiers.com or contact 1-800-332-1110.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No mist output	Empty tank/low water	Refill tank; ensure cap is tight.
White dust around unit	Hard water minerals	Use filter; try distilled water; clean unit.
Unit not turning on	Power issue	Check plug; outlet; ensure tank is properly seated.
Leaking water	Loose cap/tank damage	Tighten cap; check for cracks; replace if damaged.
Loud noise	Mineral buildup	Clean tank and base; descale with vinegar.
Poor humidity	Room size/filter	Ensure room size ≤500 sq ft; replace filter.

Reset: Unplug for 1 minute, then restart.

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