Aprilaire 600 Humidifier 17 GPD with Automatic Digital Humidistat

Aprilaire 600 Bypass Humidifier with Automatic Digital Humidistat that humidifies up to 4,000 sq feet dispersing 17 gpd!

The 600 ByPass FlowThru Aprilaire Humidifier is a whole-home solution that helps homeowners reach their optimal indoor comfort through humidity control.


The 600 bypass humidifier is designed to work in large to mid-sized homes, efficiently humidifying up to 4,000 sq feet and dispersing 17 gallons of water daily.


This bypass unit mounts directly to the duct of your heating and cooling system, allowing the humidity to be placed directly into the airflow and distributed evenly throughout the home. It can be mounted on the supply or return duct (plenum) and is also easily reversible for right or left hand installation. Additionally, this model will connect to a water line so you don't need to worry about filling it multiple times a day.


Benefits of a Bypass Humidifier


  • Prevents Flu and Allergies
  • Neutralizes Static Electricity
  • Reduces Pet Dander and Discomfort
  • Protects Fine Furniture, Wood Floors, and Musical Instruments
  • Relieves Dry Skin and Scratchy Throats
  • Reduces Heating Costs


The Aprilaire 600 bypass humidifier comes with an Aprilaire60 automatic humidistat with an outdoor sensor. The Aprilaire60 humidistat will mount directly to your heating and cooling system to accurately detect and deliver the appropriate amount of humidity to your home, while the outdoor sensor works to transmit the outdoor air temperature and humidity to the humidistat. The amount of humidity your humidistat predicts is based on a formula that factors in both the current temperature of the house and the temperature / humidity outside the home, accurately controlling the humidity of your home without any work or guessing for the homeowner. Sensing the outdoor temperature and the indoor humidity level, the automatic humidistat will call for the ideal amount of indoor humidification to ensure you and your family are as comfortable as possible.

The Aprilaire60 automatic humidistat is equipped with notification lights to quickly alert the homeowner if the system is in need of maintenance.

Red = The humidifier is not working and needs your attention.

Yellow = The humidifier's #35 Aprilaire Water Panel needs to be replaced.

Green = The humidifier is working properly.


The Aprilaire 600 Humidifier is Shipped to you as a Complete System that Includes:

1 Aprilaire 600 humidifier with a built-in bypass damper

1 #35 Water Panel

1 Model 60 Digital Automatic Humidistat (includes an outdoor temperature sensor)

1 Self-Piercing Saddle Valve

1 24 vac Transformer

Items that are not included: 6" bypass duct, copper tubing, drain tubing, and thermostat wire.


This Aprilaire 600 humidifier requires a plenum opening of 10" W by 12 3/4" H. For electrical reference, this unit operates on 24 Volts at 60Hz with a .5 AMP requirement. *Important note: If the Aprilaire bypass 600 humidifier is installed on a heat pump system it is best to connect the unit to a hot water line. Aprilaire recommends the #4839 maintenance kit be used each humidification season to ensure that your 600 humidifier is operating optimally.


In addition, using a genuine Aprilaire #35 water panel is highly suggested. This water panel was designed specifically for the Aprilaire 600 humidifier and provides the most comfortable and efficient output. Don't trust the aftermarket products to provide the same quality and overall experience as the genuine #35 Aprilaire water panel.


How to Videos


Seasonal Maintenance 
Water Panel Replacement 
Aprilaire 600 Bypass Humidifier Overview
Aprilaire 600 Bypass Humidifier Maintenance
How to change the water panel on Aprilaire 600 humidifier


If you have any questions regarding this product, please use the HVAC.com Contractor Directory to connect with a trusted contractor in your area.

  • Brand: Aprilaire
  • Genuine OEM Product: Yes
  • Type: Bypass Humidifier
  • Control Type: Automatic Digital
  • Coverage: Up to 4,000 sq. ft.
  • Water Panel: Aprilaire #35
  • Evaporative Rate: .70 Gallons Per Hour
  • Feed Rate: 3 Gallons Per Hour
  • Bypass Diameter: 6"
  • Electrical: 24V - 60Hz - 0.5AMP
  • Product Measurements: 15 3/8" W x 15 3/4" H x 10 1/4" D
  • Plenum Opening: 10" W x 12 3/4" H
  • UL Listed: Yes
  • Includes: 24V Transformer, Automatic Digital Humidistat, Outdoor Temperature Sensor, Saddle Valve, 1 Aprilare #35 Water Panel
  • This product comes with a 5 year limited manufacturer's warranty from the date of installation.
    Reviews Write a Review
    • Danr

      Got the best price on the Internet. Bought it before 5pm and got it next day by 5pm. Wow!!! DIY... I installed it myself and saved several hundreds of $$$.

    • Justchilldude

      Its not complete set, need to spend $100 more for the remaining equipment to finish the installation. Its better to buy complete set for $200 rather than spending $280 on this

    • LeeJ

      We are very satisfied with the Aprilaire 600. Installation took several hours, but the instructions were very clear (be sure to read/understand them completely before getting started!). My HVAC system was installed in the 1980s, obviously without an aftermarket humidifier in mind. This dehumidifier was the only unit available I looked at that would fit in the small space I had to work with. While I didn't get around to installing until after the driest part of the season, everything is working well, and my wife and son's hands are no longer cracking and bleeding like before. We are also relived to not be static-shocked every time we hug or shake hands in our home!

    • Michael95

      I purchased the Aprilaire 600 humidifier to replace a dying drum style humidifier. I installed it myself and I was very impressed with straight forward instructions. Installation was a breeze. With the automatic digital control, I will no longer have to keep adjusting the humidity level. Simply fantastic.

    • JoeV

      Every winter we complain about dry noses and throats. I finally decided to get the 600. It took about a week, but now our house is not as dry. Works great!

    • Guitar monkey

      Very nice unit. Wiring instructions were a little confusing for a dyi but I got it done. Very inpressed with HVAC customer service. My contro box has a terminal issue and they sent me a replacement pronto! Great internet company.

    • kodakdan

      Works great easy install and have a great place to buy from

    • Aprilaire

      Installed right in same hole from old aprilaire humidifier.

    • Tnt000000

      Great company to buy from. This was my second purchase from HVAC.com. They shipped fast. The humidifier was easy to install if you have a little mechanical ability. I've used it for a month and it works great! No issues.

    • Captain Luke

      I bought the aprilaire 600 humidifier about a month ago and have really been able to tell a difference with the quality of air in my home. No more dry throats and bloody noses. I would definitely recommend this product to a friend.

    • jmak

      I bought mid Nov.2014 noticed a difference within a few days.

    • Susan

      This humidifier is a replacement for one I had for years that never worked properly. It has a digital humidistat which shows the humidity in the house. It works so well that the furnace runs less often and I can keep the temperature lower than I have in the past.

    • pate400

      I bought it a month ago to replace a 15 year old Aprilair. Happy with the products and easy to install and very easy to follow wiring instructions with diagrams. Great customer service. Shipping is fast. Received it the next day on regular free shipping.



    • Meli

      Really cool

    • Melissa

      My husband bought this unit to replace an old outdated humidifier. Looks pretty cool and from what I hear runs automatically. I'm glad to know that we are now back to be humidified during the winter!

    • Christian

      Easy to shop, great prices. - Christian

    • Gerald

      Very good selections and easy payment.

    • Ralph

      Good Selection of products,reasonable prices, fast shipping.

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    Aprilaire 600 Humidifier 17 GPD with Automatic Digital Humidistat