Why Is My Ecobee Thermostat Fan Running Nonstop and Won't Shut Off
- Fan setting set to On instead of Auto in ecobee app
- Minimum fan runtime set too high in comfort settings
- Fan dissipation delay running fan after HVAC cycle ends
Problem Description
Your HVAC fan runs continuously and never shuts off even when heating or cooling is not active. The ecobee thermostat shows the fan as running constantly. Your electric bill has increased and the constant airflow is noisy and uncomfortable.
Symptoms
- HVAC fan runs 24 hours a day without stopping
- Fan continues running after temperature target is reached
- Ecobee display shows fan icon even with no heat or cool call
- Electric bill increased noticeably from constant fan operation
- Fan noise is constant throughout day and night
- Turning off the thermostat does not stop the fan
Recognize these? Here's what usually causes it.
Common Causes
- Fan setting set to On instead of Auto in ecobee app
- Minimum fan runtime set too high in comfort settings
- Fan dissipation delay running fan after HVAC cycle ends
- G wire issue causing fan relay to stay energized
- HVAC system fan relay stuck in closed position
- Comfort setting schedule overriding fan to always-on
Most fixes happen in the first 3 steps.
A continuously running fan increases your electric bill by 30 to 50 dollars per month. Fix this promptly. Also a fan running nonstop can wear out the blower motor prematurely requiring an expensive HVAC repair.
Tools & Requirements
These tools will help you complete this fix.
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Step-by-Step Solution
Check Fan Mode Setting
On the ecobee thermostat tap the main screen then tap the fan icon or go to the app and tap System then Fan. If set to On the fan runs continuously regardless of heating or cooling activity. Change it to Auto so the fan only runs when HVAC is actively heating or cooling. This is the most common cause and the simplest fix. The fan should stop within 30 seconds of switching to Auto.
Review Minimum Fan Runtime
Go to ecobee app then Settings then Comfort Settings. Check each comfort profile like Home Away and Sleep. Each profile has a Minimum Fan Runtime setting as a percentage. If set to 100 percent the fan runs the entire time that profile is active. Reduce to 0 percent or a reasonable value like 5 to 10 percent. High minimum fan runtime was likely set accidentally during initial setup.
Check Fan Dissipation Setting
Go to Settings then Installation Settings then Thresholds. Check the Fan Dissipation Time. This setting keeps the fan running after an HVAC cycle ends to distribute remaining heated or cooled air. If set very high the fan appears to run nonstop because cycles overlap. The default is 30 to 60 seconds. Reduce to 30 seconds or turn off if fan noise is a concern.
Inspect Wiring at Thermostat
Turn off HVAC power at the breaker. Remove the ecobee from its mounting plate. Check the G wire which controls the fan. It should be firmly in the G terminal. If the G wire is touching another terminal or there is a bare wire short the fan relay stays energized. Also check at the furnace control board that the G wire connects only to the G terminal there as well.
Test the HVAC Fan Relay
If changing all ecobee settings to Auto still does not stop the fan the HVAC system fan relay may be mechanically stuck in the on position. At the furnace there is a fan relay or switch. Some furnaces have a manual fan override switch on the unit. Check if it is set to On or Auto. If the relay is stuck closed it keeps the fan running regardless of thermostat commands. An HVAC technician can replace the relay.
Quick Solutions
Still having issues? This is usually the deeper cause below.
Schedules that skip randomly are usually a daylight-saving holdover — delete and recreate the schedule to clear the corrupted entry.
Set fan to Auto for most efficient operation. If you want air circulation without running HVAC use the minimum fan runtime at 5 to 10 percent rather than setting fan to On which runs it 100 percent of the time.
Thermostat issues that keep returning are often caused by stale backup-battery memory holding old settings across power cycles without the user realising.
- Fan setting set to On instead of Auto in
- Minimum fan runtime set too high in comfort settings
- Fan dissipation delay running fan after HVAC cycle ends
- G wire issue causing fan relay to stay energized
- HVAC system fan relay stuck in closed position
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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