Fan control with a Nest thermostat

Forced-air systems run the fan whenever they’re heating or cooling. If your forced air system has a separate fan wire in your Nest thermostat’s G connector, you can run the system fan when it’s not heating or cooling. If not, your fan will only run automatically when your system is heating or cooling. 

If you have a system with a dedicated fan wire, you can manually turn on the fan with the app or your thermostat, or set a fan schedule. For example, you can set the fan to run all night and automatically turn off in the morning.

Important things to know about fan control

If there is a wire in your Nest thermostat’s G connecto

  • You can run your system’s fan independently of heating or cooling. So your system doesn’t need to be actively heating or cooling to run the fan.
  • However, you can only run the fan when your thermostat is set to a temperature mode (like Cool mode, for example). You cannot run the fan if your thermostat is set to Off
  • You can set the fan to run a fixed schedule or manually set it to run. It can’t be set to automatically run or switch off when you leave or come home.
  • You’ll see a fan icon on the temperature screen when your fan is running because of your fan schedule, or if you’ve turned your fan on manually.

If there isn’t a wire in your thermostat’s G connector 

  • The fan can only run while your system is actively heating or cooling. 
  • You won’t see fan control options on your thermostat or in the app.

Changing fan settings can change comfort and energy savings

Running your fan for longer may help to even out the temperatures between rooms in your home, however the fan can use a lot of energy and increase your electric bill. 

Running the fan longer will increase your system’s runtime, so you may need to replace the air filter sooner. Turn on Filter Reminders to help you know when it’s time to replace your system’s filter.

Fan control with your thermostat

Fan controls differ slightly depending on which thermostat you have. Select your thermostat below.

Nest Thermostat

  1. Tap your thermostat’s touch bar and select Fan Fan.
  2. Select how long you’d like your fan to run, then tap to confirm. 
  3. Choose Start to run the fan or Cancel.
  4. Your fan will turn off automatically after the time you’ve selected, but you can turn the fan off early by selecting Stop from the fan menu.

Nest Learning Thermostat and Thermostat E

Turn your fan on manually

  1. Press your thermostat ring to open the Quick View menu.
  2. Select Fan Fan.
  3. Turn the ring to select how long you’d like your fan to run. 
  4. If you have a multi-speed fan, you’ll also be able to set your fan speed.
  5. Your fan will turn off automatically after the time you’ve selected.
  6. You can turn the fan off early by selecting Stop fan from the fan menu.

You’ll see a spinning fan icon on your thermostat’s screen to let you know it’s running.

Set a daily fan schedule

  1. Press your thermostat ring to open the Quick View menu.
  2. Select Settings Nest settings icon.
  3. Select Fan.
  4. Choose Schedule.
  5. Set how long you’d like your fan to run per hour, or set it to always run.
  6. Select what hours of the day you’d like your fan to run. If you have a multi-speed fan, you can select a fan speed for your fan schedule.
  7. Select Done to set your schedule.

Your fan will turn on automatically each day for the time and duration you’ve selected.

Change the fan speed

 Important: This setting is only available for systems with multi-speed fan controls over the thermostat wires. This affects the fan speed when your system is actively heating and cooling. You’ll have separate options to set the fan speed each time you manually turn on your fan or if you set a fan schedule.

For example, you can set your fan to high when heating or cooling and and schedule your fan to run at low speed in the morning to circulate the air in your home.

Learn more about the Nest Thermostat and multi-speed fans

Press your thermostat ring to open the Quick View menu.

  1. Select Settings Nest settings icon.
  2. Select Fan.
  3. Choose System fan speed.
  4. Select the fan speed you’d like to use when your system is heating or cooling your home. Depending on your system you may see Low, Medium, High or Auto, if you have a multi-speed fan.

Choose Done to set your system’s fan speed.

Fan control with the Home app

Turn your fan on manually

  1. Open the Google Home app Google Home app.
  2. Tap the thermostat you’d like to control.
  3. Tap Fan Fan, then Set fan timer.
  4. Choose how long you’d like your fan to run. 
  5. Tap Start to run your fan or Cancel.
  6. Your fan will turn off automatically after the time you’ve selected, or you can turn it off early by selecting Set fan to Auto from the fan menu.

Set a daily fan schedule

  1. Open the Google Home app Google Home app.
  2. Tap the thermostat you’d like to control.
  3. Tap Settings .
  4. Select Schedules and then Fan.
  5.  Switch Run every day on if you want to set the same fan schedule for all days. Set it to off if you want a unique schedule for a particular day.
  6. Choose a start and end time with From and To.
  7. Set how long you’d like to run your fan per hour. You can choose 15, 30, 45 minutes of run time, or select 60 minutes to run your fan for the whole hour. 

Your fan will turn on automatically each day for the time and duration you’ve selected. You can always edit or disable your schedule at any time from the fan menu.

Fan control with the Nest app

Turn your fan on manually

  1. Tap the thermostat you’d like to control from the home screen.
  2. Tap Fan Fan.
  3. Select how long you’d like your fan to run. If you have a multi-speed fan, you’ll be able to select your fan speed.
  4. Tap Start to run your fan.

Your fan will turn off automatically after the time you’ve selected, or you can turn it off early by selecting Stop from the fan menu.

Set a daily fan schedule

  1. Tap the thermostat you’d like to control from the home screen.
  2. Tap Settings Nest settings icon.
  3. Select Fan Schedule.
  4. For Every day, tap the slider to turn your fan schedule on or off.
  5. Set how long you’d like to run your fan per hour. You can choose 15, 30 or 45 minutes of run time, or select 60 minutes to run your fan for the whole hour.
  6. Choose what time you want your fan to start running, and when you’d like your fan to stop running this schedule. If you have a multi-speed fan, you can select a fan speed for your fan schedule.

Your fan will turn on automatically each day for the time and duration you’ve selected. You can always edit or disable your schedule at any time from the fan menu.

Change the fan speed

Important: This setting is only available for systems with multi-speed fan controls over the thermostat wires. This affects the fan speed when your system is actively heating and cooling. You’ll have separate options to set the fan speed each time you manually turn on your fan or if you set a fan schedule.

  1. Tap the thermostat you’d like to control on the app home screen.
  2. Tap Settings Nest settings icon.
  3. Select Fan.
  4. In HVAC fan speed, select the fan speed you’d like to use when your system is heating or cooling your home. You can choose Low, Medium, High or Auto, depending on your system’s wiring.

If you choose low, medium or high:

  • Your fan will always run at that speed when heating or cooling your home.

If you choose Auto:

  • Your Nest thermostat will automatically choose how fast to run your fan when heating or cooling your home.

You’ll still be able to choose a different speed for your schedule and each time you manually run your fan. For example, you can set your fan to high when heating or cooling and use a schedule to set your fan to low every morning to circulate air in your home.

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