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

Ecobee Thermostat

The Ecobee Smart thermostat is a great device to have controlling your HVAC system, but as we all have experienced sometime in our life, technology doesn’t always work the way we want it to. One of those situations I ran into recently was when Ecobee wasn’t turning on the Fan to the HVAC system.

If your Ecobee in not turning on the fan check that the wires are correctly connected and snug, check the Ecobee settings that control when the fan runs, and check the continuity of wires running between the furnace and the Ecobee Thermostat. You can short the Power and Fan wires to test the Fan.

Having the fan turn on is important. IF the fan does not turn on, heat generated by the furnace will not be distributed! Every situation is different, but these steps should help you diagnose the problem. For the purpose of this article, we are talking specifically about fan issues and assuming that the rest of your HVAC system is working properly as far as you know.

It isn’t necessary to follow the steps in order, but may save you time. If you suspect as specific problem, go ahead and jump to that section. Do what makes the most sense for the problem you are having.

Trouble Shooting When Your Ecobee Fan Won’t Turn On

I mentioned just a moment ago that we want to check the wires for a proper connection and for continuity, and check the Ecobee settings to make sure they’re setup to use the fan.

The first step is actually going to be the last tip I mentioned; Shorting the Power and Fan wires to test the Fan. Doing this test will check for a handful of problems along the way. Here is the order I recommend going in.

  1. Test the Fan
    • Includes Resetting Ecobee
    • Includes Checking Continuity of the Wires
    • Includes Checking Wiring for Proper Connection
  2. Check Ecobee Thermostat Settings

How to Test Your Furnace Fan Is Working When You Have An Ecobee?

This article is specific to Ecobee, but this step is not. The only specific part to Ecobee is how to remove it from the wall.

There are several reasons this step is first. The main reason this step is first is to confirm that the furnace fan does indeed function still. It will save you a lot of time from going into Ecobee’s settings and trying to figure out why it’s not turning on the fan. If the fan is broken, it’s not going to turn on even if your settings are correct!

Secondary reasons are that it resets the Ecobee, and it is a quick way to check continuity of the wiring between your thermostat and furnace fan.

The reason for resetting the Ecobee is that sometimes software has glitches. Ever get the blue screen of death on your computer?! Ecobee is pretty reliable, but even the best software is going to have a few bugs.

If you aren’t familiar with continuity checking of wires, let’s go over it really quick. When a wire has continuity, it means that it is not broken. It is able to pass a signal from one side to the other. IN this case we are checking the fan wire, which needs to have continuity between the thermostat (Ecobee), and the furnace control board. If your Ecobee is turned on, we already know that the Power and Common wires have continuity.

The last thing I want to mention is that I am assuming your wires are connected in the standard way. The two we will be using are green and red. The green wire goes to the fan, and the red wire is the power. If you are unsure about how they are connected, you can check on your furnace control board. Green should go to G and Red should go to R. They should be connected in the same way to the terminals on the Ecobee base plate.

Read Also: Ecobee Not Cooling: 12 Major Reasons and Best

Steps to Check that Furnace Fan Works

  1. Remove Ecobee from the wall

    This can be done by pulling the Ecobee straight out from the wall. Make sure you aren’t grabbing the base plate, as that is screwed into the wall.
  2. Check that the Wires Are properly connected

    There are a couple of ways to do this. One is checking in Ecobee’s settings (we’ll do that later if needed), and the other is to check the physical connection, which we’ll do right now.

    The wires should be securely attached to their respective terminal on the Ecobee base. You can check by giving them a little tug. If they slide out, that means they weren’t inserted correctly.

    To insert the wires properly, you need to push down on the tap opposite the side of where the wire is inserted, put in the wire, and let go of the tab. The tab will not spring back up when the wire is inserted. Give the wire a little tug again to make sure it’s in there.

    If any of the wires were not properly inserted, in particular the Red and the Green wires, it would be worth while to reinstall the Ecobee and check the fan really quick. If it works, you’re done. If not, remove the Ecobee again proceed to the next step.

    I should also mention that if you are using the Power Extender Kit (PEK), make sure all those wires are properly connected as well. You will need to check the wires coming from the thermostat, and well as the wires coming from the PEK to your furnace control board.
  3. Touch the Green wire to the Red Wire

    Caution! The wires are hot! Don’t touch the bare metal part or you will be shocked.

    These wires operate at 24 Volts, so it won’t be like sticking a finger in a 120 Volt outlet, but you will still feel it!

    To complete this step, you will need to remove the green wire from its terminal by pushing down on the tab and giving a firm pull on the wire so that it comes out of the hole. Again, be careful because the green wire is right next to the live red wire.

    If you would feel more comfortable, turn off power to your HVAC system before handling the wires, and then turn it back on when you are ready to touch the wires together.

    If the red wire has some copper exposed, touch the green wire to the red wire. If the red wire does not have any copper exposed, remove it from the terminal and then touch the two wires together.

    The result should be that the fan turns on. You should be able to hear when the fan turns on, and air will start blowing through the vents.

What to do if the fan Doesn’t turn on?

If your fan does not turn on, that means your Ecobee is NOT the problem. It is either the green wire, or a problem with the fan or furnace. You can check the green wire by using a continuity tester, or by connecting it to the power terminal and using a multimeter to check the voltage.

If the wire has continuity, it’s time to call in the HVAC professionals. Brace yourself for a large bill if they have to repair or replace parts of the furnace. HVAC equipment is never cheap, and neither is the labor.

If the wire does not have continuity, you can try running a new wire yourself. Or again, calling a professional.

What to do if the fan does turn on?

If the fan does turn on, that’s great news! It means the problem is likely something with your Ecobee. Reattach the wiring, push back on the Ecobee, and move to the next step: Checking Ecobee Settings

Wait…. you just said it was great news. Yes, I said that because you won’t have to replace any expensive HVAC equipment, or run any new wires. The worst-case scenario now is that you have to replace your Ecobee, which is cheap compared to all the other equipment and you don’t have to pay for any labor to replace it.

How to Check Ecobee’s Fan Settings

After completing the last step, Ecobee will have rebooted when you reattached it to the wall. Check the fan just to make sure it wasn’t fixed by rebooting the Ecobee. There are now a couple places we need to check from within Ecobee. Here is the order we will go in.

  1. Check Ecobee’s interpretation of how the wires are connected
  2. Check Ecobee’s Fan Control in Heat Mode

Ecobee does have more fan related settings, but they do not apply to our problem of the fan not turning on. These other settings deal with how long the fan stays on and if the fan is always on.

How to Check Wiring from Ecobee Menu

Ecobee has a quick way that you can check the wiring without removing Ecobee from the wall. Here is how you do it.

  1. Open the Main Menu

    When you walk up to the Ecobee thermostat, it will change from the Stand-By screen to the Home Screen. To open the Main Menu, you will need to tap on the icon that looks like three parallel lines, located in the lower left corner.
  2. Select “Settings”

    This is the second from the bottom menu option on the firmware version I have.
  3. Select “Installation Settings”

    This will open the page where you can see the advanced settings that can only be changed on the thermostat itself. Not in the app or web app.
  4. Select “Equipment”
  5. Select “Wiring”

    The Ecobee will display the wires, and highlight the ones that it detects connected in a white box. You can’t change them from here, but you can at least confirm that it matches up with your equipment.

    Here are how wires are commonly connected for a forced air system with an air condition:
    • Blue – C – Common wire.
    • Red – Rc – 24VAC power
    • Green – G – Fan
    • White – W – Heat
    • Yellow – Y – Air conditioner

If the wires don’t show up as expected you will need to reset your Ecobee and set it up again with the expected configuration, or go back up to the “Equipment” and then select “Reconfigure Equipment”. Also, check the physical wiring connections if you haven’t already.

How to Check Ecobee’s Fan Control in Heat Mode

This is the last troubleshooting step in the arsenal. Ecobee has the option of having Ecobee control the fan, or letting the HVAC system control the fan.

If your furnace is designed to turn on the fan when there is a call for heat, then you want your HVAC control board to control the fan. This is common on system with variable speed fans. In the event that your furnace can’t control the fan, then it has to controlled by the Ecobee.

There’s a simple way to test if your HVAC system has a fan that is controlled by the HVAC system itself. Short the R and W wires. If the fan comes on, then you know that the furnace controls the fan when it receives a call for heat. If you are unsure of how to short the wires, refer back to the steps I listed to check if the furnace fan works. Just remember, you are shorting R and W, not R and G. White turns on the heater, Green turns on the fan.

If the fan does not come on, then you should let Ecobee control the fan.

Steps to Select Fan Control in Heat Mode on Ecobee

  1. Open the Main Menu

    When you walk up to the Ecobee thermostat, it will change from the Stand-By screen to the Home Screen. To open the Main Menu, you will need to tap on the icon that looks like three parallel lines, located in the lower left corner
  2. Select “Settings”

    This is the second from the bottom menu option on the firmware version I have.
  3. Select “Installation Settings”

    This will open the page where you can see the advanced settings that can only be changed on the thermostat itself. Not in the app or web app.
  4. Select “Equipment”
  5. Select “Furnace”
  6. Select “Fan Control in Heat Mode”

    The Ecobee will give you two options:
    • Ecobee thermostat
    • HVAC
  7. Select the proper option for your system.


Hopefully you have your fan up and running after working through these troubleshooting steps. We just went through a bunch of steps, so if the fan is not working yet, take a step back, relax, and come back and review later to make sure you checked everything correctly. I realize how frustrating it can be when you are either hot or cold, and need the HVAC system running. I hoe you were able to get the issue fixed.