Aprilaire Model 8840 Automation Thermostat with IAQ Control

Industry’s first color touch screen with all control options on the home screen.

The Aprilaire Model 8840 Automation Thermostat with ​IAQ Control has:

  • Universal 3H/3C or 4H/2C HP
  • Event-Based™ Air Cleaning
  • Humidity and Ventilation
  • 2 Part - 3-Wire design
  • Wi-Fi with full color touch screen
  • Compatible with Amazon Alexa and Google Assistant *when not integrated in a home automation system


Event‐Based™ Air Cleaning

When paired with an Aprilaire whole‐home air purifier, the Aprilaire Model 8840 Wi-Fi Thermostat allows you to clean your home's air on your terms with Event‐Based™ Air Cleaning. This is perfect for allergy and asthma sufferers and for times when your air is more contaminated than usual—for example, when pollen counts are high or you're churning up dust when vacuuming. 

Event‐Based Air Cleaning includes four options for purifying your air: Constant Clean runs 24/7, Automatic runs for a minimum of 30 minutes every hour, Event Clean runs for three hours, and Allergy runs for 24 hours and then returns to the most recent mode.


Not only do Wi-Fi thermostats give you the ability to modify your home’s temperature from any mobile device, the Aprilaire scheduling and program over-ride provide the usability needed to save money—without sacrificing comfort.

Air Purity

The air you breathe inside your home can be the most polluted air you breathe all day. People who suffer from asthma and allergies will benefit from the ability to control air cleaning—especially with the unmatched simplicity of Aprilaire’s exclusive Event-Based™ Air Cleaning feature.


Too much or too little humidity can play a big role in your comfort and health.

Automatic Humidifier Control

Continuously monitors outdoor temperature while automatically adjusting the humidifier to provide optimum levels inside the home. Manual control is also available, if needed.

Automatic Dehumidifier Control

Automatically turns on a dedicated dehumidifier based on relative humidity. It couldn’t be any simpler.

Energy Savings*, Comfort and Convenience

The Aprilaire Model 8840 Home Automation Thermostat is easy to program and helps you save money on energy costs by allowing you to set back the temperature during the night or when you're away. Multiple hold options maximize comfort and energy savings:

Fresh Air Ventilation

Fresh air ventilated from the outside is required in many new homes. That’s why Aprilaire controls are designed to meet all ASHRAE 62.2-2010 requirements. Simply set the parameters and the control will ventilate the proper amount of air. Event-Based™ is also available for those who want additional fresh air for circumstances such as cooking or parties.

Energy Savings

You control when and how your heating and cooling systems work - saving you time and money.

Total Air Control

With leading technology, Aprilaire thermostats are digital and provide laser-like accuracy.

Mobile Access

Have control and easy access so your indoor air quality (IAQ) is just a click away.