Honeywell HE205A1000
24V Large Bypass Humidifier w/ H8908 Manual Humidistat 17 GPD
  12GPD 17GPD

Honeywell HE205A1000 17GPD large bypass humidifier with H8908 manual humidistat. Suitable for homes up to 20,000 cubic feet in size.

Enhance, protect and maintain your home’s most comfortable humidity level with a Honeywell Whole-house Humidifier. Proper humidity provides a more comfortable living environment at a lower temperature, so you can turn down your thermostat for energy savings. Controlling humidity also means moisturizing dry air to prevent damage to hardwood floors and woodwork while preventing excess moisture.


  • Whole-house bypass flow-through humidifier
  • With AgION™ antimicrobial pad
  • Electrical rating: 24 VAC, 60 Hz, 0.5A
  • Includes H8908 manual humidity control
  • "C" models include complete installation kit
  • 3-year warranty

Dimensions 18.30 × 17.11 × 9.59 in.
(465 × 434 × 243 mm)
Duct Opening 12 5/8 in. x 9 3/4 in.
(321 mm x 248 mm)
Temperature Range 41 to 113 °F (5 to 45 °C)
Includes Humidifier, H8908 manual humidistat, 24V Transformer
Mounting Duct
Power Consumption 24VAC, 60 Hz, 7 watts with 24 Vrms
Type Evaporative Flow-Through Humidifier
Capacity 17 gal per day
Flow Rate At Nozzle 4.7 GPH under 120 psi

What is Flow-Thru Humidifier?

The term Flow-Thru refers to water trickling through the water panel and out a drain. The advantages of a flow-thru design is reduced maintenance and no standing water. Scale from calcium and lime gets flushed out of the water panel and down the drain. The water panel is an aluminum mesh with a porous coating that inhibits growth of slime and is easy to change (once a year).

The disadvantage of the Flow-Thru is water usage. We are in the northeast where this is not an issue. We get a flat rate water bill unless there is excessive usage then the rate goes up. The Flow-Thru humidifier does not cause excessive usage.

The Flow-Thru is an evaporative humidifier and requires hot air. If not using hot air then hot water should be used. We see little humidity gain if our Flow-Thru humidifier is operating with cold air (and cold water). We run our blower on constant to best utilize our electronic air cleaner, but our humidifier is wired to only operate only when there is hot air and works very well.
Flow-thru Humidifier Type Demostration

By-Pass Versus Power Humidifier

By-pass Humidifier Demostration
Power Humidifier Demostration
The term By-Pass or Power refers to the driving force behind the air flow. The Fan-Power humidifier uses a fan to draw the air thru the humidifier. The ByPass humidifier uses a 6" diameter duct that connects the supply to the return duct.

In the ByPass configuration the air leaving the furnace is routed back to the supply. The warm air leaving the furnace takes this short-cut of least resistance and bypasses the long trip down the duct work, in to the house, and back through the return. The ByPass is the 6" round duct work shown to the left. During the the hot humid A/C season the ByPass duct should be closed with a butterfly valve since the air flow through the humidifier would not be needed.

The Power humidifier uses a fan to draw air in from the duct and through the humidifier and exhausts back out in to the duct. The air is drawn in through duct at the center of the humidifier and back out in to the duct at the sides. The power humidifier should be mounted in vertical warm air flow.

The HE100A, HE150A, HE200A and HE250A are ByPass humidifiers. The HE300A is a fan powered humidifier.

Manual Versus Automatic Humidistat

The indoor humidity level needs to be set based on the outside temperature. This is to prevent water from running down the windows. The cool air near the windows can not hold the humidity and water will condense on the glass. To prevent this condensation, the indoor humidity level is sacrificed by lowering the humidistat.

A manual humidistat needs to be set back as the season gets colder. An automatic humidistat (such as the Aprilaire 60) adjusts the humidity by using an outside temperature sensor.

The Honeywell HumidiPRO automatic humidistat (H6062A) provides automatic humidification or dehumidification for central heating and air conditioning systems. HumidiPRO™ will automatically adjust settings for changes in outdoor temperature to ensure no condensation will appear on your home windows.

Outdoor Temperature Recomended Relative Humidity
+40°F (4°C) 45%
+30° (-1°C) 40%
+20° (-7°C) 35%
+10° (-12°C) 30%
0° (-18°C) 25%
-10° (-2-3°C) 20%
-20° (-29°C) 15%

Honeywell TrueEASE Warranty

Honeywell Five year Warranty for Replacement PartsThe Honeywell warranty for the HE205A humidifier is 3 years. Our customers simply ship us the defective part. We inspect and test and confirm defective. We then ship back a brand new part.

The problem with humidifiers is typically due to water quality problems. The solenoid will corrode or freeze up with calcium deposits. The solenoid has an inline filter that when clogged with sediment will tear and pieces of the filter will jam the solenoid.

The warranty does not cover problems with calcium and scale.

Shopping Cart
Your cart is empty.
Browse Categories
1 BBB Customer Reviews