Nest Temperature Sensor Won’t Connect? Here’s How To Fix

Whenever the Nest temperature sensor won’t connect you should inspect the entirety of your setup.

In this post, we’ll uncover the right way to connect the sensor, followed by a series of solutions that will exclude ALL possibilities one by one.

At the end of the guide, your temperature sensor will be connected or you will know where the problem is.

The Nest temperature sensor will not connect if your Bluetooth is not turned ON or if there is another active connection. There could be wireless interference or the thermostat cannot communicate with the smart app.

There is much more to this problem than just this, so let’s attempt to connect your sensor using the right steps and then proceed with the solutions.

How To Connect The Sensor Correctly?

Chances are you’re not doing the setup process correctly.

Before we troubleshoot the sensor, it’s recommended that you undergo the entire setup process all over again and make sure you’re not letting any mistakes slip by.

Here’s how to hook up the Nest temperature sensor to the thermostat the correct way:

1. Within the Nest app, hit the Settings icon.
2. Once redirected to the settings, tap on “Add Product”.
3. Choose “Scan QR Code” to add a device.
4. Go over to the Nest temperature sensor and expose its QR code.
5. Remove the battery pull tab (if already removed, unscrew the backplate to expose the QR code).
6. Scan it using the camera on your phone.
7. Wait for Nest to add your temperature sensor.
8. Pick the thermostat you wish the sensor to associate with.
9. Choose the room name where the temperature sensor is located.

Important: Keep in mind that the Nest temperature sensor is only supported by Google Nest thermostat E and 3rd gen learning thermostats.

How To Fix When Nest Temperature Sensor Won’t Connect To Thermostat?

Now when you’re confident that the setup process is made the right way, it’s time to look for the problem.

Our solutions will help with the task of identifying and solving the problem if followed in order.

Tip: It’s also recommended not to skip any of them so you won’t miss anything essential to the process.

Solution #1 Turn On Your Phone’s Bluetooth

During the setup process, your phone must have a turned-on Bluetooth connection to get the sensor and thermostat linked.

Since these devices use a Bluetooth connection over WiFi to communicate with each other, your phone is the mediator for creating the signal.

In that regard, here’s how to turn on Bluetooth both on iOS and Android:

• For Android phones, go to Settings > WiFi & Connectivity > Bluetooth > Turn On/Enable.

• For iPhones & iPads, go to Settings > Bluetooth > Enable.

Tip: When enabling the Bluetooth on your phone, ensure that you don’t get automatically hooked up to other devices.

Solution #2 Move The Sensor Closer

Since the Nest temperature sensor connects with the thermostat via Bluetooth and not WiFi, the distance between both units really comes into necessity here.

Your average WiFi signal can keep its strength for over 100 meters, while the Bluetooth signal breaking point is only at 30 meters.

Chances are that you installed the sensor too far away from the thermostat and both devices cannot connect via Bluetooth.

In this solution, we suggest unmounting the sensor from its current location and possibly placing it closer to the thermostat.

It’s also recommended to have it in the same room as the thermostat, but many users don’t find this solution comforting.

It’s enough to be in the 25-30 meters range from the thermostat, for the Bluetooth connection to existing.

Alert: If you’re reinstalling the thermostat during this step, make sure to put it on a flat surface.

Solution #3 Remove Wireless Interference

The wireless interference is all around your household and can be caused by a variety of objects.

In this solution, we will familiarize you with all matters of interference that can impact the connection between your sensor and Nest thermostat.

Here’s what to avoid placing your sensor next to:

• Laptops
• Smart TVs
• Cordless phones
• Microwave ovens
• Portable speakers
• Other Bluetooth devices
• Baby monitors
• Smartphones

If it’s not possible for you to avoid all of the following, it’s enough to keep any other Bluetooth devices away from the temperature sensor and the thermostat as well.

Notice: Bluetooth devices that have their Bluetooth turned on all of the time mean more harm to the connection of the sensor.

Solution #4 Re-Add The Thermostat From The Nest App

If you’re still unable to get the sensor hooked up with your Nest thermostat, it’s likely that the thermostat got disconnected from the Nest app.

If that happens, you should re-add the thermostat and attempt to connect the temperature sensor once again.

Here’s how to re-add your Nest thermostat from the application in easy steps:

1. Go to the Nest app.
2. Head over to “Devices”.
3. Tap on the Nest thermostat that you intend to connect the sensor to.
4. Choose “Device options”.
5. Tap on “Remove”.
6. Next, press the plus sign in the devices tab.
7. Choose the model of the thermostat from the list.
8. Follow the on-screen instructions to re-add the thermostat.

Note: Once ready, you should attempt to get the sensor hooked up using the instructions at the beginning of the post.

Solution #5 Replace Nest Temperature Sensor Battery

If you still haven’t managed to get the sensor linked to your thermostat, it’s most likely due to a dead battery within the sensor.

Nest temperature sensors use a CR2 3V Lithium battery, which isn’t expensive and can be found in tech stores in your local area.

Alert: To replace the battery, you will need a coin to insert in the lock and spin to unlock the battery cover.

Here’s how to replace the sensor’s battery in easy steps:

1. Unmount the sensor.
2. Grab the coin.
3. Insert it into the lock.
4. Spin towards the left side.
5. Pull the battery cover off.
6. Eject the old battery of the sensor.
7. Insert the fresh 3V battery.
8. Reinsert the battery cover of the sensor.
9. Test the device.

Note: Mind the polarity of the battery and how you put it into the compartment.

Solution #6 Reset The Nest Thermostat

The problem tends to be with your Nest thermostat, rather than with your sensor if the setup still fails.

The best approach at this point is the factory reset process that you can apply to the thermostat to reset all of its settings.

Here’s how to reset the Nest thermostat in step-by-step:

1. On your thermostat, go to the Quick View menu.
2. Choose Settings.
3. Turn the ring once and select RESET.
4. Turn again to choose ALL SETTINGS.
5. Confirm to proceed with the reset.
6. Wait for the thermostat to reset.

Note: On average, a reset takes around 2-5 minutes.

Whenever the Nest temperature sensor can’t connect, start by executing the setup process using the correct steps. Proceed with moving both devices closer to each other and preventing any Bluetooth interference. Lastly, inspect the sensor’s battery and factory reset the thermostat.

Read Next: How To Fix Nest Thermostat Fan Not Working Issue?

Bottom Line:

Now when you know why Nest temperature sensor won’t connect and how to solve the problem you should be ready in no time.

In case the problem persists, you may need to contact Nest customer service for more information about the problem.