Nest Support

Questions about Nest Learning Thermostat or Nest Protect: Smoke + CO alarm? We've got answers, videos, and plenty of resources to help you out.

How do I set up Nest to work with my whole-home humidifier or dehumidifier?

The 2nd generation Nest Learning Thermostat is compatible with most whole-home humidifier and dehumidifiers. However, professional installation is strongly recommended.

Humidifier or dehumidifier systems compatible with the 2nd generation Nest Learning Thermostat are controlled by a single wire connected to the Nest Learning Thermostat’s connector.

Why do I need professional installation?

Some whole-home humidifier or dehumidifer systems connect to the thermostat with one wire, while others have two. If yours has two wires, a professional installer may need to add a relay to convert it to one wire.

Your installer will figure out if your humidifier or dehumidifier can be activated on its own or if it requires heating or cooling to be activated at the same time. Your installer will also determine other settings such as whether the fan is required during operation.

In addition, your installer will choose the right settings for your system in Nest’s Pro Setup, which can be found by choosing SETTINGS and then EQUIPMENT.

IMPORTANT NOTE: Choosing the incorrect options for a humidifier or dehumidifier can result in system damage, so it’s important for a professional to assess the requirements for your specific system.

Ask your installer what options they have chosen for your system so you’ll have them handy should you ever need to re-enter them yourself.