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Ecobee Not Cooling: 12 Important Reasons and Troubleshooting

Last Updated: November 15, 2023

Are you searching for the answer to why is your Ecobee not cooling? You are in the right place. With my years of experience in the field of electronics, I’ll highlight 12 core problems behind this Ecobee issue and provide a hands-on guide on this topic. Let’s have a look!

ecobee not cooling

Quick Answer

To give you a quick insight, I have renovated almost 20+ Ecobee thermostats. Nearly all of the faulty devices have the following common problems:

  1. Tripping in circuit breakers;
  2. Sensors not working;
  3. Issues with fuses;
  4. Loose wiring.

However, the above troubles are just the tip of the iceberg. Continue reading below, where I have discussed 12 main issues behind your thermostat not cooling, along with a hands-on troubleshooting guide. Moreover, there will be some additional tips on how to prolong the life of your unit. Let’s get into it!

A Quick Glance at 12 Reasons Why Your Ecobee Not Cooling to Set Temperature

I don’t mind being a little warm when I’m outside, but I really don’t like being warm when I’m at home. Here are the most common reasons Ecobee fails to cool your house. Let’s find out:

Possible Cause

Main Fix

Wrong thermostat settings

Switch the modes as per your heating or cooling preferences

Wrong thermostat wiring

Replace the fuse or swap out the frying wires

Condensation problems in the AC

Clear the clogged pipes

Malfunctioned reverse valve

Look for obstruction in the valves and remove them

Malfunctioning control board

Ensure the control board is receiving full power and correct voltage

Issues with the AC's filters

Replace the disposable filters every 1-3 months or clean washable filters

Troubles with the float switch

Ensure no clogging in the drain pipe and the float switch is not tripped

Coolant leakage

Get professional help to get rid of coolant leakage

Dirty AC coils

Remove the dust from the coils with the help of the brush

Wrong compressor minimum outdoor temperature

It is dangerous to change any settings yourself, contact a professional

Compressor minimum cycle off time is incorrect

Keep compressor minimum runtime setting at 300 seconds

Faulty Equipment Configuration

Examine the faulty sensors or loose connections and resolve them

Justin Vargas

The first thing to do in the case of the Ecobee thermostat not cooling is to check the thermostat settings. You may be surprised, but almost a third of customers have had the problem due to incorrect values.Justin Vargas, Founder and Writer, Electrical Engineer

1. Wrong Thermostat Settings

Incorrect thermostat settings are common issues resulting in cooling issues in your HVAC filter system. Signs that your thermostat settings are wrong may include incorrect temperature, wrong mode, or scheduled program conflicts.

A Quick Glance at 12 Reasons Why Your Ecobee Not Cooling to Set Temperature

To correct it and ensure your HVAC filter system functions as intended, I recommend the next: 

  1. Verify that the temperature displayed on the thermostat matches your comfort needs. 
  2. If not, switch the mode to align with your cooling requirements. 
  3. If you have a programmable thermostat, review your schedules.
  4. After making the necessary adjustments, test the HVAC filter system.
  5. Wait a few minutes to see if the temperature changes according to your adjustments. 

Read Also: What to Do When Your Ecobee Fan Won’t Turn On

2. Wrong Thermostat Wiring

The Ecobee air conditioner’s inability to cool may be attributed to incorrect thermostat wiring. This issue can hinder the system from functioning optimally, leading to discomfort during hot weather. However, neither I nor you would like to be in this situation. To address this problem, it is crucial to identify and rectify any wiring errors. Here’s how you can do it:

Check for a Blown Fuse

The first step to troubleshooting the issue is to check for a blown fuse. A blown fuse can disrupt the electrical flow, affecting the cooling system’s operation. To resolve this, follow these steps:

  • Step 1: Find the fuse in your HVAC filter system. It is typically located in the disconnect box near the outdoor unit or the main electrical panel.
  • Step 2: Carefully remove the fuse and inspect it to see if the wire (R, G, Y, W, and C wire) inside the fuse is broken or discolored.
  • Step 3: If the fuse is blown, replace it with a new one with the same amperage rating. 
  • Step 4: After replacing the fuse, turn the power back on and check if the AC gives cold air and operates correctly. 
Check for a Blown Fuse
Check for a Blown Fuse (2)

Inspect The Wiring for Fraying

When you’re inspecting the blown fuse, check for the frayed wiring. To ensure the system’s wiring is in good condition, follow these steps:

  • Step 1: As a safety precaution, turn off the power to the HVAC system.
  • Step 2: Inspect the wiring connected to your Ecobee air conditioner and thermostat. Look for visible signs of fraying, damage, or exposed wires.
  • Step 3: If you find any frayed wires, carefully repair or replace them. Use electrical tape or wire connectors to secure and insulate damaged wires.
  • Step 4: Once the wiring is in good condition, restore the power to the HVAC system and test the air conditioner’s cooling performance. 
Note: If you need help removing your Ecobee thermostat, check out my article here on how to uninstall an Ecobee.

3. Condensation Problems in the Air Conditioner

The most common cause of your AC not turning on is excessive water build-up from condensation within your system. Your filter system has a drain pan or drain line.

Now you know what it is if you’ve ever seen a pipe sticking out the side of your house, occasionally dripping water. Over time, mold, algae, and dirt can build up inside these pipes and pans.

Read Also: Why Isn’t My Ecobee Fan Turning Off? Why is it Always On

Condensation Problems in the Air Conditioner

Add to it that dirt tends to stick to water, which causes build-up to happen faster. A safety device will trigger if the water level gets too high. When triggered, power to the thermostat and air conditioner will be cut off.

Why Water Drain?

There are several reasons why the water in the drain pan may begin to build up:

  • The line can get knocked out of place;
  • Bacterial growth might clog the drain;
  • Dust and dirt build-up.

When build-up occurs, the shallow drain pan, which is about 2 inches deep, will start to overflow and spill out into your home. HVAC professionals will advise you NOT to try and repair the problems yourself. They warn that a mistaken fix can end up causing additional leaking, resulting in more costly and prolonged damage.

Justin Vargas

One of the main causes of Ecobee not cooling to a set temperature could be clogged drain lines. Check them and clean if necessary.Justin Vargas, Founder and Writer, Electrical Engineer

However, I take their advice with a grain of salt. Clearing a clogged pipe isn’t that complicated. So, if you suspect any obstruction in the drains, clear it using a distilled vinegar solution like Heinz Distilled White Vinegar. Follow these steps to clean with vinegar:

  • Step 1: Disconnect the drain pipe;
  • Step 2: Pour the vinegar down and let it run the whole length;
  • Step 3: Once you’re done with this, reattach the drain pipe and use the thermostat to determine if the problem is resolved. 
Important! But if you’re unsure what the problem is, then I would recommend contacting the pros.

4. Malfunctioned Reverse Valve

Reserve valves, or reversing valves, are critical components in heat pump and air conditioning systems. They enable the system to switch between heat and cool mode. When reserve valves encounter issues, it can disrupt the system’s ability to provide comfort and energy efficiency.

Follow these steps to ensure that the reverse valves are working fine:

  • Step 1: Go to the Main Menu on your thermostat display and click on Settings;
  • Step 2: Head towards Installation Settings and choose Equipment;
  • Step 3: Pick a Heat Pump and select O/B Reversing Valve. If the thermostat gives heat in cold mode, you must seek an HVAC professional to resolve the problem.

5. Malfunctioning Control Board

The control board is a crucial component of an HVAC system, responsible for regulating and coordinating the functions of various AC system components. When the control board malfunctions, it can disrupt the entire system’s performance, leading to issues with heating, cooling, and overall operation.

Malfunctioning Control Board

Let’s have a wider picture of how to deal with it. 

  1. Inspect if the control board is receiving a consistent 24VAC power supply and electrical connections are secure – such as no loose wires or blown fuses in the system.
  2. Use a multimeter such as the KAIWEETS Digital Multimeter to check if the control board receives the correct voltage from the power source.
  3. Some control boards are programmable and require firmware updates. Check if an outdated firmware version is causing issues and update it if necessary. 
Pro Tip: Read this guide to find out how to update the firmware.

6. Issues With the AC’s Air Filters

The purpose of an AC filter is to clean the air and trap the micro-particles. However, during its service period, it can also succumb to various issues like clogging due to dust particles. Let’s learn how you can inspect the faulty AC air filters and treat them:

  • Step 1: Start by understanding the filter type, including the disposable (replaceable) or washable (reusable). 
  • Step 2: Locate the filter access panel in your AC system, typically near the furnace or air handler.
  • Step 3: Examine the filter visually. Look for accumulated dust, debris, or signs of wear and tear. 
  • Step 4: Check the manufacturer’s recommendations for filter replacement or cleaning frequency. Replace disposable ones every 1-3 months, while washable ones can be cleaned and reused.
  • Step 5: You can also consider upgrading to a high-efficiency or HEPA filter.
  • Step 6: While the filter is removed, inspect the filter for housing for leaks, gaps, or damaged seals. 

Take help from this guide to find out how to precisely swap the air filters.

7. Troubles With the Float Switch 

When you have a clogged drain pipe, the float switch is also at risk. This switch keeps a check on the water levels or humidity levels. There are chances that your system may malfunction if the float switch trips closed for no apparent reason. To tackle this:

  • Step 1: Ensure the switch is not tripped and check for clogs in the drain lines. 
  • Step 2: Follow the cable attached to the R terminal on the control board of the furnace or air handler unit to locate the switch.
  • Step 3: Turn it off and see if the system empties regularly.
  • Step 4: Once it is done correctly and the draining process resumes, use the thermostat to determine if the problem has been fixed. 

8. Coolant Leakage

The coolant is one of the most important parts of an AC. It is responsible for cooling and removing excess heat from the room. Therefore, it should be high on the list of things to check, if your thermostats show any signs of disturbance. To check for coolant leaks, do the following:

  • Step 1: First, look at the coolant pipes’ joints.
  • Step 2: Once it is located, use soapy water to determine if there are any leaks.
  • Step 3: When you find bubbles in the water, it indicates that the coolant is leaking and requires your immediate attention.
  • Step 4: However, to fix this, you would need professional help. So, please don’t waste time and contact with them.

9. Dirty AC Coils

Although copper is a very good heat conductor, corrosion can still occur if your AC coils are slightly exposed to the outside elements.

If the coils are dirty for a longer time, it can significantly affect the performance and efficiency of your air conditioning system. Over time, dust and debris can accumulate on the evaporator and condenser coils, reducing heat transfer and cooling capacity.

Dirty AC Coils

Do the following to clean the dirty coils:

  • Step 1: Look for the dust and debris to clean it off.
  • Step 2: Sometimes, it might be challenging to see the dirt with the naked eye. For that, use a flashlight. 
  • Step 3: To avoid dirty coils in the first place, consider installing filters in the return air ducts and maintain a regular filter cleaning schedule.
  • Step 4: Use a soft brush or coil cleaning solution to clean the coils, or follow the manufacturer’s instructions to avoid damaging the coils.

10. Ecobee Thermostat Not Cooling due to Wrong Compressor Minimum Outdoor Temperature

This temperature determines the lowest temperature at which your compressor will function. Usually, it’s set to 35°F/1.7°C.

However, before adjusting this setting, I strongly recommend contacting your heat pump or compressor manufacturer to ensure you’re using a safe threshold. Because operating the compressor below its specified temperature can lead to equipment damage.

Justin Vargas

If your Ecobee thermostat not cooling due wrong compressor’s minimum outdoor temperature it’s necessary to connect with the manufacturer or pros. Changing the settings yourself can be dangerous.Justin Vargas, Founder and Writer, Electrical Engineer

11. Compressor Minimum Cycle Off Time is Incorrect

The ‘Compressor Minimum Runtime‘ is the shortest time your compressor will run. By default, it’s set to 300 seconds (5 minutes). If you cancel a call while your compressor is on, it will run for a full 5 minutes before turning off.

This prevents short cycling, which can damage the compressor. Therefore, it’s recommended to keep this setting at 300 seconds for compressor protection.

12. Faulty Equipment Configuration

The equipment configuration in various systems and appliances is critical to their proper functioning. Inspecting this helps ensure all components are correctly set up and adjusted. Follow the next steps: 

  • Step 1: Start with visually inspecting the equipment’s physical components;
  • Step 2: Look for any loose connections, damaged parts, or missing elements. 
  • Step 3: Go to Settings > Installation Settings > Equipment > Wiring;
  • Step 4: Find out if RC and RH are highlighted. If only R or Y1 is lighting, you need to configure the settings.

Here is how you can configure the thermostat:

  • Step 1: Head towards Installation Settings > Equipment > Reconfigure equipment;
  • Step 2: If only R is connected, select “Yes, only RC is connected;”
  • Step 3: If only Y1 is connected, select none;
  • Step 4: Go to Modify, select the terminal that you want to configure, and hit Next. Once you are done, you’ll see the respective terminal is connected.

How to Reset Your Ecobee Thermostat?

Resetting your thermostat is typically done in situations where you need to start from scratch or resolve issues with the thermostat’s configuration. It is very simple and you will handle it without difficulty. Here’s how to reset your Ecobee thermostat to its factory settings:

  1. Access the thermostat’s menu and navigate to “Settings”;
  2. Select “Reset”;
  3. Choose “Reset All Settings”;
  4. Confirm the reset;
  5. Reconnect to Wi-Fi and reconfigure your preferences.
How to Reset Your Ecobee Thermostat_1
How to Reset Your Ecobee Thermostat_2

Read Also: What Is Fan Runtime on Ecobee? Recommended Settings & Minimum Runtime

Contact Ecobee Support First Before an HVAC Professional

If you are an Ecobee customer, they provide free support. So, unless you have an HVAC emergency, I’d recommend contacting Ecobee first to try and get your issues resolved. Having HVAC service people out to your house is not cheap. It costs them time and money, which they pass on to you. They’re a business, so I don’t blame them, but even a simple fix could cost you over $100.

The latest information for Ecobee support can be found on their support website here. They have phone, chat, e-mail, and Twitter as support options if you can’t find the answer on their support page.

I know this article has been about fixing Ecobee problems, but if you want to know more about why I still recommend Ecobee, check out my recommendation page here.

How Long Do Ecobee Thermostats Last?

Ecobee thermostats are known for their durability and typically have a lifespan of around 10 years. However, the actual lifespan can vary depending on factors such as usage, maintenance, and environmental conditions. Nonetheless, if you want to prolong the life span of the thermostat do:

  1. Regular maintenance;
  2. Software updates;
  3. Proper care.

Moreover, if you notice any issues or reduced performance, it’s advisable to consult Ecobee’s customer support for a professional technician to assess and address any problems.

Does Ecobee Thermostat Need C Wire?

Ecobee thermostats do not always require a C-wire (common wire), but the need for one depends on the specific model of the thermostat and your HVAC system. However, to ensure optimal performance and compatibility, Ecobee recommends having a C-wire.

Does Ecobee Thermostat Need C Wire

A C-wire provides a dedicated 24V power supply to the thermostat, eliminating any potential power issues or the need for power-stealing. This is particularly important if you have a complex HVAC system or if your thermostat requires more power due to additional features, such as a touchscreen or Wi-Fi connectivity.


Why is my Еcobee not cooling?

Your Ecobee not cooling can be due to low coolant levels, a faulty compressor, or a dirty filter.

Why is my thermostat on cool but not cooling?

Your thermostat is not cooling because there will be some issue with the thermostat setting or your coils will be clogged up. It is recommended to reset the thermostat and clean up your jammed coils.

How do you know if your Еcobee thermostat is bad?

Your thermostat is bad if it’s getting too hot, detecting the wrong temperature, or simply displaying an error message.

What to do if Еcobee thermostat is not working?

If the Ecobee thermostat is not working, check its wiring section and perform a reset. If the issue still persists, get in touch with Official support.

Should Ecobee be on auto or cool?

You should run Ecobee on auto but if you are living in a warmer region, then you can also opt for the cool mode. It depends on your personal preference

Why is my AC not cooling to the thermostat setting?

If your AC is not cooling to the thermostat setting, it can be due to jammed-up coils or a dirty filter. Also, look out for the duct leaks and make sure your unit is located in the central part of the house.


Summing up, Ecobee’s not cooling is due to many reasons which include condensation problems, a wrongly configured thermostat, dirty or clogged air filter. You can reset your thermostat or clean the filter to fix these issues.

In case, your issue is related to incorrect compressor minimum outdoor temperature, malfunctioning reverse valve, or coolant leakages, it is recommended to not take matters into your own hands and seek the help of an HVAC technician. Remember, your safety comes first!

Recommended read: 

Can an HDMI Splitter Extend the Display To 2 Monitors

How to Set and Adjust the Temperature on Ecobee