Smart thermostats like Ecobee are designed to maintain comfort levels with minimal effort on your behalf. But sometimes, you may find out that your Ecobee is not cooling to the set temperature, has been on for too long and hasn’t produced the result expected, or the home stays warmer than it should. This issue is very common—and thankfully usually easy to fix.
In this article, you will learn why an Ecobee may not cool properly, how to diagnose each cause, and the step-by-step solutions to restore proper cooling. Whether you are a complete beginner, a homeowner, or a technician, this article equips you with all you need to troubleshoot confidently.
Common Signs Your Ecobee Is Not Cooling Properly
Some potential symptoms of an issue affecting your Ecobee’s control over the AC include:
- Your house remains warmer than the set temperature.
- AC operates continuously but does not cool
- AC doesn’t turn on at all
- Wrong temperature displayed on thermostat
- Cooling cuts on and off frequently
- A “calibrating: heating and cooling disabled” message
- Ecobee shows cooling mode but the unit outside is silent
This could be a sign of problems associated with the thermostat, AC equipment, sensors, wiring, or HVAC airflow.
Also read: Nest vs Ecobee
Why Your Ecobee Isn’t Cooling to the Set Temperature: Top Causes Explained
Following are the 12 most common causes of the problem and how each can be resolved.
1. Incorrect placement of temperature sensors
Ecobee SmartSensors help to balance temperatures room-to-room. However, if a sensor is placed poorly, it may think that your home is cool:
Common placement mistakes
- Near windows exposed to sunlight
- Close to cold air vents
- In kitchens where appliances produce heat
- Near exterior doors
- In bathrooms
Correct
- Move the sensor to an interior wall
- Place it 4–6 ft above the ground
- Avoid direct sunlight, kitchens, vents, and hallways
Check the setting for Follow Me. If it’s turned on, Ecobee uses sensors only in occupied rooms. Turn this off, if necessary.
2. Frozen or Dirty Evaporator Coils
A frozen indoor coil prevents proper cooling and causes temperature imbalance.
Signs
- Low airflow from the vents
- Ice on refrigerant lines
- Water leaking near AC
- AC runs constantly
Correct
-Turn the AC off for 2–3 hours and allow it to defrost
-Replace the air filter.
-Assure all vents are open.
-Schedule a technician for refrigerant and coil check
3. Poor Airflow or Clogged Vents
If your HVAC system can’t handle moving cold air effectively, then your Ecobee will struggle to reach setpoint.
Correct
- Open all supply vents
- Remove furniture obstructing airflow
- Replace filters every 30–60 days
- Clear debris around the outdoor AC condenser
A weak airflow alone can prevent your home from cooling down.
4. Improper Thermostat Settings
Ecobee settings may prevent cooling, even when the AC is on.
Check these settings:
Cooling Mode
Go to:
Menu → System → HVAC → Cool
Make sure it’s on Cool or Auto.
Temperature Hold
Remove any temporary or permanent holds.
AC Overcool Max
With this feature set to zero, Ecobee may stop early.
Adjust it under:
Settings → Installation Settings → Thresholds → AC Overcool Max
5. Ecobee Thermostat Calibration Issues
Ecobee, on reboot or installation, may display “Calibrating: Heating and Cooling Disabled.”
Calibration takes 10–20 minutes. But if it never ends, your thermostat may be reading temperatures incorrectly.
Fix
- Reboot Ecobee: Menu → Settings → Reset → Restart
- Ensure thermostat is not near heat sources.
If it is continually reading the temperature wrong by 2–3 degrees, either recalibration or replacement may be necessary.
6. Wiring Issues
If the cooling wires are loosely attached or not fitted properly, then the AC doesn’t respond.
Fix
(Only if comfortable—otherwise call a professional.)
- Power off HVAC at breaker
- Remove Ecobee faceplate
- Confirm that wires are fully inserted.
- Y1 wire must be connected to enable cooling
- Ensure that RC/RH wiring is correct
- Reattach and power on
Incorrect wiring is one of the most overlooked causes of cooling issues.
7. Low Refrigerant Levels
If your AC leaks refrigerant, it will run consistently with no cooling.
Signs
- Air is cool but not cold.
- AC runs for hours
- Ice on refrigerant line
- Hissing sound at condenser
Correct
Any refrigerant repairs need an HVAC technician.
8. Dirty or Damaged Outdoor Condenser
When the outdoor AC unit is clogged, the system cannot release heat, which results in poor cooling.
Fix
- Switch off power
- Hose off the condenser gently
- Remove debris, leaves, grass
- Leave at least 2 feet of clearance around the unit
A dirty condenser can reduce cooling efficiency by over 30%.
9. The HVAC System is Undersized for Your Home
If you’ve recently renovated, expanded rooms, or added heat-producing appliances, then your AC may no longer be strong enough.
Correct
Only a load calculation-otherwise known as a Manual J test-can determine proper AC capacity.
10. Ecobee “Smart Recovery” Delaying Cooling
Smart Recovery predicts when your home needs cooling, starting early so you reach the desired temperature on time.
Sometimes, this feature delays cooling unintentionally.
Correct
Turn off Smart Recovery:
Menu → Settings → Preferences → Smart Recovery → Off
11. Stage 2 Cooling Not Operating (Two-Stage Systems)
If your system supports two-stage cooling, say Y1, Y2, but stage 2 never kicks in, your AC might be challenged during very hot weather.
Correct
Check:
Menu → Settings → Installation Settings → Equipment
Ensure that Stage 2 Cooling is activated.
A technician may be required to check on Y2 wiring and equipment compatibility.
12. AC or Heat Pump Power Issues
If your condenser is not receiving power, your Ecobee thinks it’s cooling, but the outdoor unit does not run.
Fix
- Check AC breaker
- Ensure outdoor disconnect switch is on
- Look for blown fuses.
If the outdoor unit is silent, then this may be the cause.
Also read: Honeywell T9 Smart Thermostat
How to Troubleshoot Ecobee Not Cooling (Step-by-Step Checklist)
Follow this quick diagnostic process:
Step 1: Check Thermostat Mode → Cooling
Step 2: Check temperature sensors for wrong placement
Step 3: Check if AC is physically running
Listen for the outdoor unit.
Step 4: Replace the air filter
Dirty filters are the #1 airflow issue.
Step 5: Check your vents and registers
Make sure they are open and unobstructed.
Step 6: Reboot Ecobee
A simple reboot sorts out software issues.
Step 7: Reset system settings
Go to installation settings → thresholds.
Step 8: Wiring inspection
Ensure Y1, RC/RH are correctly connected.
Step 9: Check for frozen coils
Switch off AC, then check the refrigerant line.
Step 10: Clean the outdoor unit
Remove debris, ensure proper airflow.
Step 11: Disable Smart Recovery
Prevents delayed cooling.
Step 12: Call a technician
If refrigerant, compressor, or capacitor issues are suspected.
Prevent Ecobee Cooling Issues Before They Happen
To prevent issues later, take heed of the following tips:
- Replace filters monthly
- Keep sensors in ideal locations
- Clean the outdoor unit twice a year.
- Schedule annual HVAC maintenance
- Avoid covering the vents
- Update your Ecobee firmware
- Use a whole-home surge protector
Proactive care leads to better cooling and prolongs AC life.
FAQs: Ecobee Not Cooling
1. Why is my Ecobee blowing warm air?
If your AC is blowing warm air, the system may be low on refrigerant, wiring may be wrong, or the thermostat is not in cooling mode.
2. Why does my Ecobee take so long to cool the house?
Common reasons may be dirty filters, blocked-up vents, undersized AC, or Smart Recovery delaying cooling.
3. Why does Ecobee say it’s cooling, but the temperature doesn’t change? This could be due to a frozen coil, weak airflow, poor sensor reading, or refrigerant leak.
4. Can Ecobee control a two-stage AC? Yes, Ecobee supports single-stage, two-stage, and variable-speed systems. Just ensure that both Y1 and Y2 wires are properly connected.
5. Should I reset my Ecobee? Yes, it can. A soft reset will work out calibration and communication issues without affecting your saved schedules.
Final Thoughts
Usually, an Ecobee that is not cooling to the set temperature will be because of a simple cause: incorrect settings, sensor problems, or airflow restrictions. You can quickly identify the problem and restore full cooling performance by following the troubleshooting steps in this guide.
If these remedies are insufficient, then the air conditioning system is mechanical in nature and may need the expertise of an HVAC professional. In most cases, homeowners can solve this problem without very expensive repairs.
