My Amazon Smart Thermostat Has A Red Exclamation Point! – Why? What To Do?

Did you notice the red exclamation point on the screen of the Amazon smart thermostat? What does it mean? We did comprehensive research to answer your question.

The red exclamation point on the screen of the Amazon smart thermostat indicates that it's running low on power. Also, the unit will automatically shut down until it has sufficient power again. Simply replace the batteries with the steps below:

  1. Find and press the button at the bottom of the thermostat.
  2. Open the battery cover.
  3. Pull the old batteries out, then replace them. You need two "AA" batteries.

Please continue reading as we'll talk about the Amazon smart thermostat and what the icons on the screen mean. Then, we'll discuss more on other relevant matters. 

the body of a connection thermostat with the electrical wires through it. - My Amazon Smart Thermostat Has A Red Exclamation Point! - Why? What To Do?

My Amazon Smart Thermostat Has A Red Exclamation Point! 

Smiling Indian woman using modern smart home system, controller on wall, positive attractive young female switching temperature on thermostat or activating security alarm in apartment.

Amazon's smart thermostat helps many houses monitor the room temperature. It has features such as icons, in which a red exclamation point means your smart thermostat has insufficient power and will turn off soon.

To resolve such a red exclamation point, you'll want to replace the batteries as discussed in the steps we've provided above.

See this "AA" batteries on Amazon.

What Is a Yellow Exclamation Point on Amazon Smart Thermostat?

A yellow exclamation point indicates that there's a notification waiting for you in the app. You should browse the app on your mobile phone to find such notifications. 

How to Connect the Amazon Smart Thermostat With Mobile Phone

Connecting your mobile phone with the thermostat grants you easy and quick access to the thermostat's features. So, see below the steps on how to do it:

  1. Find the Alexa App on your mobile phone.
  2. Read the app description for compatibility.
  3. Download the app. Make sure you have an internet connection or mobile data to download successfully.
  4. Launch the Alexa App, then click the "MORE" button.
  5. Press the "ADD DEVICE" button. Under the list of devices, select "THERMOSTAT."
  6. There's a portion where the screen shows the list of brands of thermostats. Simply choose "Amazon."
  7. A question on the screen will appear whether you installed the thermostat already or not. By pressing "NO," you will be redirected to the installation guide. While pressing "YES" will proceed to connect the thermostat with the Wi-Fi.
  8. Follow the instructions that will appear on the screen. Simply provide the thermostat's information to finish the task. 

Does Amazon Smart Thermostat Need a C-Wire?

HVAC Technician repairing digital heating and cooling thermostat.

The C-wire, or common wire, keeps the thermostat powered by supplying a constant amount of electricity into the unit. With a C-wire, you don't have to replace the batteries unless the batteries are defective or drained.

You should check if the unit is connected to the C-wire. However, you can add one for your thermostat. But before doing so, it's important to understand further what the C-wire can do to the thermostat. See the features below.

Constant Power Supply

As mentioned earlier, the C-wire provides constant electricity of 24 volts for the thermostat. For instance, there's a power shortage in your area. The C-wire can prevent the thermostat from getting damaged caused by a sudden cut of power.


Modern thermostats have advanced features that activate only by connecting the unit to the Wi-Fi. Without the C-wire, you cannot connect the thermostat to your mobile device.

How to Add C-Wire on Amazon Smart Thermostat

the body of a connection thermostat with the electrical wires through it

There are two ways to add the C-wire. Check below, and choose one for your convenience.

Repurpose an Existing Wire

You can find a common wire in your house's wiring system, then convert it into a C-wire for your thermostat. Remember to consult an electrician if you're worried about electrical safety.

However, you can also use the G-wire as an alternative to C-wire. Simply follow the steps below on how to do it:

  1. Turn off the main power supply.
  2. Access the control board of the HVAC unit.
  3. Connect the wiring terminals R, G, Y, W, and C on the furnace control board.
  4. Transfer the G-wire into the C terminal.
  5. Connect the 18-gauge thermostat wire from the Y terminal to the G terminal.
  6. Put the cover on the HVAC control board.
  7. On the thermostat, move the R, Y, and W wires to their respective terminals.
  8. On the thermostat again, connect the G-wire to the C terminal.
  9. Reconnect the thermostat and turn the circuit breaker on.
  10. Proceed to connect the thermostat to the internet.

Use a C-wire Adapter

A C-wire adapter is a ready-to-use product that has a complete set of wires for the thermostat. This is convenient to use, especially if you don't have much time to do the first option.

See this C-wire adapter in Amazon.

See below the steps on how to use a C-wire adapter:

  1. Turn off the HVAC unit and its thermostat as well.
  2. Unscrew the thermostat's faceplate to reveal the wires inside.
  3. Take a picture of how the wires are arranged. You'll need this for reference.
  4. Unscrew the cover of the HVAC unit to see the wires.
  5. Take also a picture of wires on the HVAC unit, then label these wires according to the codes.
  6. Detach the wires from the HVAC unit and connect them to the C-wire adapter at the "thermostat" side.
  7. Find the "equipment" side of the adapter, then connect the wires there to the HVAC unit.
  8. Place the C-wire adapter near the HVAC controls unit.
  9. Go to your Amazon smart thermostat and label the "G" wire as "C." Then label the "Y" wire as "K."
  10. Disconnect such wires from the previous step, then connect them to C and K terminals, respectively.
  11. Put back the thermostat cover.
  12. Turn on the thermostat and the HVAC unit.

Watch a video of the demonstration here:


How to Reset the Amazon Smart Thermostat

Resetting the thermostat is a quick way to put the settings back to zero. Meaning, you can set up the thermostat again like it's your first time seeing it. Should you want to reset the thermostat, simply do the steps below:

  1. Put your three fingers on the bottom and hold for a while until you see the screen display change.
  2. Release the hold, then put your finger on the center button. Wait until the countdown stops.
  3. You can now reset the thermostat by changing the temperature and other features.

Watch this short clip for your visuals:

How Smart is the Amazon Smart Thermostat?

It's relevant to understand what makes the Amazon smart thermostat a "smart" device. That's why we listed down some advanced features you can enjoy with this unit. Check these features below.

Alexa Voice Control

You can conveniently control the thermostat using your voice. This is a nice feature, especially for those who prefer contactless control. You just need a few clicks to activate this feature. Follow the steps below:

  1. Download and launch the Alexa app.
  2. Go to the settings and find the option for recognized voices.
  3. Enable automatic voice recognition.
  4. Proceed to create the voice profile. You should read the message that will appear on the screen with your normal voice. Also, minimize background noise.
  5. Once done, you can add another voice profile from another person. Simply log in with their account to make a new voice profile.

Modern Design

Amazon smart thermostat is quite simple yet elegant in design. There are no protruded buttons in the faceplate, unlike other thermostats. This can easily match the color and theme of the house since it's minimal in appearance.

See this Amazon smart thermostat.

Amazon Smart Thermostat Warranty

Beautiful woman push button digital thermostat at house

You're granted a limited warranty of one year for your smart thermostat. This covers manufacturing defects and system failure. But if the damage is due to broken parts caused by negligence, then the product is no longer warranted.


We learned in this article the meaning of red exclamation points, as well as other features of the Amazon smart thermostat. We provided steps for adding a C-wire to the unit, and how to activate the voice command.

Are you looking for more articles like this? Feel free to visit us here:

How To Install Amazon Smart Thermostat Without C Wire [Step By Step Guide]

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