How to Install Your Ecobee Smart Thermostat and Power Extender Kit

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If you’ve recently purchased an ecobee thermostat, this article will guide you through the step-by-step process of removing your existing thermostat and installing the ecobee smart thermostat along with the Power Extender Kit. Whether you have a C wire or not, this article will provide you with all the necessary instructions to complete the installation.

Step 1: Installing the Power Extender Kit

Before starting the installation process, make sure you have a Philips head screwdriver and wire label stickers handy. Here are the steps to install the Power Extender Kit:

  1. Remove the panel of your furnace or air handler to locate the control board.
  2. Use a screwdriver to carefully loosen the screws on the control board and disconnect the wires.
  3. Take a photo of the wires to help you remember which terminals they were connected to.
  4. Label the wires connecting to the R, W or W1, G, and Y or Y1 terminals on the control board using the labels provided with the Power Extender Kit.
  5. Ignore any wires connected to terminals other than R, W or W1, G, and Y or Y1 on the control board.
  6. Connect the wires you disconnected from the control board to their corresponding locations on the Power Extender Kit. Ensure they are securely connected.
  7. Connect the five white wires coming out of your Power Extender Kit to their corresponding terminals on the control board.
  8. Mount your Power Extender Kit to a metal surface inside your HVAC system using the magnetized back. Be careful not to strain the wires.
  9. Close the door to your HVAC equipment’s control panel. Ensure it is closed correctly to power on your thermostat.

Step 2: Completing the Thermostat Installation

Now that the Power Extender Kit is properly installed, you can proceed with the thermostat installation. Follow these steps:

  1. Decide whether you want to use the large trim plate to cover any paint marks or holes left by previous thermostats.
  2. Align the mounting holes on the trim plate and backplate, and press them into place together if using the trim plate.
  3. Position the ecobee thermostat backplate over the existing wire hole to ensure that the previous screw holes are covered.
  4. Use the built-in level on the backplate to ensure it is level, then mark the location of the mounting holes on the wall with a pencil.
  5. Drill two holes and mount the backplate using the drywall plugs and screws provided.
  6. Carefully insert your R, RH, or RC wire into the RC terminal, G wire to the C terminal, and Y wire to the PEK terminal.
  7. Using the labels as a guide, connect the remaining wires to the designated terminals on your new thermostat backplate.
  8. If you only have one R wire, connect it to the Rc terminal instead of the RH terminal.
  9. Ensure the wires are inserted correctly by checking the levers on the terminals. They should lower when the wires are installed correctly.
  10. If a wire is inserted into the wrong terminal, press down on the lever and gently pull out the wire before connecting it to the correct terminal.
  11. Tug on the wires gently to ensure they are securely installed.
  12. Push any excess wiring back into the wall recess so that the thermostat sits flat against the backplate.
  13. Line up the thermostat with the mounted backplate and press it gently until it clicks into place. The back of the thermostat should be flush with the backplate and should not wobble.

Step 3: Powering Up Your Ecobee Thermostat

Once the thermostat is securely installed, you can power it up by following these steps:

  1. Turn your HVAC equipment and circuit breaker back on.
  2. Your ecobee thermostat will come to life and be ready for use.


Congratulations! You’ve successfully installed your ecobee smart thermostat along with the Power Extender Kit. If you have any questions or need further assistance, don’t hesitate to reach out to the ecobee support team at 1-877-932-6233 or visit their website at

Remember to always refer to the official ecobee installation guide for the most accurate and up-to-date instructions. Enjoy the benefits of your new smart thermostat and its energy-saving features!