ecobee

How to control your HVAC system's fan with your ecobee thermostat

This article applies to all ecobee thermostats except Smart, Smart SI, EMS and EMS SI.

ecobee thermostats can control your fan in a variety of ways to maximize your comfort. Below we explain the five methods available.

 

Fan Control in Heat Mode

You can choose either the ecobee thermostat or your furnace to control your system's fan during furnace/aux heating cycles. When set to "thermostat", the ecobee will operate your system fan differently than your furnace during heating cycles by sending the signal to run the fan itself rather than relying on the furnace to do so.

To adjust this setting, go to MAIN MENU > SETTINGS > INSTALLATION SETTINGS > EQUIPMENT > FURNACE > FAN CONTROL IN HEAT MODE

 

NOTE: This option is only accessible through the thermostat interface. Neither the mobile apps or Web Portal provide access to adjust this option.

 

 

 

Set to ecobee thermostat: By choosing this option, your ecobee will energize the fan directly during heating cycles. This will cause the fan to immediately turn on when a heating cycle is initiated, and continue to run until the heating cycle ends.

Set to HVAC: By choosing this option, your ecobee will relinquish control of the fan to the furnace during heating cycles. In this case, there will usually be a brief delay before the fan engages after a heating cycle is initiated. This option is recommended if you have a variable fan speed furnace.

Fan Minimum On Time

This feature allows you to define the minimum amount of time each hour that the system fan will run. This feature is useful if you wish to circulate the air throughout your home automatically outside of heating or cooling cycles.

The ecobee will divide the "Fan Min On time" you select throughout each hour. If the Fan Min On Time is set for 15 minutes or lower, the fan will operate in two separate segments across the hour; if the Fan Min On Time is set for 20 minutes or higher, the fan will run in four equal segments across the hour.

If a heating or cooling cycle operates within any given hour, the length of either cycle will be deducted from the Fan Min On Time. For example, if your cooling runs for 5 minutes and your Fan Min On Time is set to 20 minutes, 5 minutes will be deducted from the Fan Min On Time.

To adjust this setting go to MAIN MENU > SYSTEM > FAN

NOTE: If you are adjusting the Fan Minimum On Time value and you have a Hold on your thermostat (meaning, you have set a temperature manually), you will first need to cancel the existing Hold before the new Fan Minimum On Time value will be applied. Afterwards, you can set a Hold again.

 

 

Quick Changes

From the Quick Changes menu, you can switch the fan to ON, overriding the schedule.

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NEW - Timed Fan Holds (new to firmware version 4.6.25 and up)

With the release of firmware version 4.6.25 and up, the Quick Changes menu has changed to accommodate the following new features:

Fan Holds can be set for the following durations: 15 minutes, 30 minutes, 45 minutes, 1 hour, 2 hours, or Indefinitely (keeps the ecobee in ON fan mode until the Hold is cancelled from the main screen with the temperature displayed)

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To use this new feature (currently only available on the thermostat screen, coming soon to the app):

  1. Tap the Quick Changes menu icon (the gear icon with 3 lines on the bottom of the thermostat screen)
  2. Tap the Fan Hold button
  3. Using the horizontal dial, select a preferred time duration for the fan to run in ON mode
    1. (Optional) If you have multi speed fan capability on your ecobee, select a fan speed from the menu below
  4. Tap the < in the top left to leave the menu
  5. Exit the Quick Changes menu

Your ecobee should now say "Fan on until" followed by the end time of the fan Hold. For example, if it is 9:00PM when you place a Fan Hold for 45 minutes, the ecobee will say "Fan on until 9:45PM"

NOTE: If there was a Hold on the thermostat prior to the Fan Hold being placed, the thermostat may not display the expected "Fan on until" text and will instead show the currently held temperature. However, the fan will still be set to ON, and the Quick Changes menu will show the fan running under the "Equipment running now" section.

 

Heat/Cool Dissipation Time 

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MAIN MENU > SETTINGS > INSTALLATION SETTINGS > THRESHOLDS > HEAT/COOL DISSIPATION TIME

The amount of time after a call for heating or cooling that the fan will continue to run. This is set to Auto by default, meaning that the furnace will decide when to disengage the fan after a heating or cooling call. The furnace may continue to run the fan for several minutes after a call for heating or cooling to expel any hot or cold air remaining in the ducts.

If set to 0 the fan will turn off as soon as a call for heating or cooling has concluded.

NOTE: This option is only accessible through the thermostat interface. Neither the mobile apps or web portal provide access to adjust this option.

 

Fan mode in Comfort Settings

Your ecobee also has the ability to control the fan mode for specific Comfort Settings such as Home, Away, and Sleep.

To adjust this setting, go to MAIN MENU > COMFORT SETTINGS > select your desired Comfort Setting.

 

 

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The ecobee has two modes of fan operation: Auto and On

  • When the fan is set to Auto, the ecobee will run the fan on equipment calls and to fulfill any remaining fan runtime required to fulfill the Fan Minimum On Time value set in Fan Duration under MAIN MENU > SYSTEM > FAN DURATION
  • When the fan is set to ON, the ecobee will run the fan constantly until told to stop or until a Comfort Setting with "Auto" fan settings is active

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