Why Is My Ecobee Fan Running on Its Own Without a Heating or Cooling Call?
- Fan minimum runtime setting configured to run fan X minutes per hour
- Ecobee Ventilate with Fresh Air feature on a schedule
- G wire connection shorting or independently energised at furnace
Problem Description
Your HVAC fan is running constantly or at regular intervals even when the Ecobee thermostat is not calling for heating or cooling. The fan runs in fan-only mode without any temperature differential requiring it. This is caused by the Ecobee fan minimum runtime setting being configured, the Ventilate with Fresh Air feature running on a schedule, or the G wire being independently energised by a wiring issue.
Symptoms
- HVAC fan runs continuously without any heating or cooling call
- Fan cycles on for short periods at regular intervals throughout the day
- Ecobee shows heat or cool off but fan indicator shows running
- Fan runtime is much higher than expected in Ecobee reports
- Fan was running occasionally before but now runs constantly
- Fan runs at night when no one is adjusting the temperature
Recognize these? Here's what usually causes it.
Common Causes
- Fan minimum runtime setting configured to run fan X minutes per hour
- Ecobee Ventilate with Fresh Air feature on a schedule
- G wire connection shorting or independently energised at furnace
- Fan Hold mode accidentally enabled in Ecobee settings
- Ecobee Follow Me feature adjusting comfort profile causing fan
- Circulation setting in Ecobee configured for high fan run percentage
Most fixes happen in the first 3 steps.
Do not disable all fan runtime settings if you have allergy sufferers in the home. Some circulation is beneficial for air quality. Reduce fan runtime to a reasonable level rather than eliminating it completely.
Step-by-Step Solution
Check fan setting mode
Open ecobee fan settings and verify the fan is not configured to run continuously or for extended minimum runtime per hour. Many 'random fan' complaints are scheduled circulation settings, not faults.
Review comfort profile overrides
Inspect active comfort settings and Smart Recovery behavior that can pre-run airflow for temperature balancing. These automation layers can start the fan before a visible heat/cool call.
Verify HVAC G-wire behavior
Confirm wiring on G terminal is stable and not shorting or cross-contacting adjacent conductors. A wiring fault can energize fan relay independently of thermostat intent.
Check third-party integrations
Temporarily disable Home Assistant, Alexa, or other automations that may be sending hidden fan commands. External control loops frequently cause recurring fan-only cycles.
Clear overrides and retest cycle
Cancel active holds, reboot ecobee, and monitor one full schedule period. If fan still runs unexpectedly with clean settings, HVAC control board diagnosis is next.
Quick Solutions
Still having issues? This is usually the deeper cause below.
If this comes back after following these steps, check whether a recent app or firmware update reset a default setting — the fix works, but the setting gets reverted silently.
Use the Ecobee energy reports to review actual fan runtime per day. A healthy system should run the fan between 4 and 8 hours per day in moderate weather depending on the home size.
This issue almost always looks more complex than it is — the majority of cases trace back to a single setting, a stale credential, or a default that shipped wrong.
- Fan minimum runtime setting configured to run fan X
- Ecobee Ventilate with Fresh Air feature on a schedule
- G wire connection shorting or independently energised at furnace
- Fan Hold mode accidentally enabled in Ecobee settings
- Ecobee Follow Me feature adjusting comfort profile causing fan
Before you go — try one of these (they fix most cases).
Most popular upgrades chosen by Ecobee Smart Thermostat owners.
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Official Manufacturer Manual
Ecobee provides official product documentation through their online manual rather than downloadable PDF. Access setup guides, troubleshooting steps, and product specifications for your Ecobee Smart Thermostat.
Source: ecobee.com
Need More Help? Ecobee Support
Note: The contact information below connects you directly to Ecobee's official customer support team, not Trunetto. They can help with warranty claims, device replacements, and advanced technical issues.
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