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Ecobee Not Cooling But Fan Is Running? Here’s How to Fix It

🌀 If your Ecobee thermostat shows that it’s running, the fan is spinning, but your house isn’t getting cooler, you’re not alone. This issue can be frustrating, especially on hot days when you rely on your AC. The good news is, it’s usually something simple—and fixable.

This guide walks you through why your Ecobee might not be cooling while the fan runs and how to troubleshoot the issue step-by-step.

đź’ˇ Why This Happens

When your fan is running but there’s no cool air, it generally means your system’s air handler is working, but your compressor or cooling stage is not. This could be due to wiring, settings, a delay timer, or even a problem with your AC unit.

🔍 Step-by-Step Troubleshooting

Check the Thermostat Settings

Start with the basics:

  • Open the Ecobee thermostat screen
  • Make sure it’s in Cool or Auto mode
  • Set the target temperature at least 3°F below the current room temperature
  • Go to Menu > System > HVAC and confirm “Cooling” is enabled

If it’s set to Heat or Off, it won’t activate the AC.

Wait 5 Minutes for Compressor Delay

Ecobee has a built-in compressor delay to protect your system. When cooling is activated, the thermostat may wait up to 5 minutes before sending power to your AC’s compressor.

You’ll typically see a gray snowflake icon during this delay.

What to do: Give it a few minutes to see if the cooling starts.

Inspect the Equipment Settings

Check if your Ecobee is actually calling for cooling:

  • Go to Menu > Settings > Equipment
  • Look for “Cool Stage 1” under the device info
  • If it says “Inactive,” your system isn’t receiving a signal to cool

Try adjusting the set temperature and observe if the cooling stage becomes active.

Check for Wiring Issues

Improper wiring, especially with the Y wire (cooling signal) or C wire (common power), can cause the AC to not respond.

  • Turn off power to your HVAC system
  • Remove the Ecobee faceplate
  • Confirm wires are connected properly to the base plate terminals
  • Y1 (cooling), G (fan), Rc/Rh (power), and C (common) should be secure

If a wire is loose or disconnected, reconnect and try again.

Test the Outdoor Unit

If the fan is running indoors but you hear nothing outside:

  • Check if the outside AC unit is humming or clicking
  • If the unit is silent, the problem could be a tripped breaker, blown capacitor, or failed contactor

Flip the HVAC breaker off and back on to reset it.

Change the Fan Setting to Auto

If your fan is set to On, it will keep blowing air even when cooling isn’t active.

  • Go to Menu > System > Fan
  • Change it from On to Auto

This ensures the fan only runs when the compressor is also cooling.

Check the Air Filter and Vents

A clogged air filter or closed vents can restrict airflow, making it feel like the AC isn’t working even when it is.

  • Replace dirty filters
  • Make sure supply and return vents are fully open

Reset the Thermostat

As a last resort, perform a thermostat reset:

  • Go to Menu > Settings > Reset > Reset All Settings
  • Follow the on-screen steps

This can clear glitches from a recent update or configuration issue.

Contact a Technician

If none of the steps above work, the issue may be with the compressor, control board, or low refrigerant levels. Contact an HVAC technician to run a full diagnostic.

âś… Final Thoughts

If your Ecobee fan is running but the air isn’t cool, it’s usually a settings issue, a wiring problem, or a delay. Start simple: check thermostat mode, wait 5 minutes, and inspect the outdoor unit. In most cases, this problem can be resolved without needing a professional—just a bit of DIY troubleshooting.