Troubleshoot a TD003, TD004, TD009, TD018, TD023, TD027, TD028, or TD030 error code for Nest thermostat

You may get a TD003, TD004, TD009, TD018, TD023, or TD030 error when you add a Google Nest thermostat to your account in the Nest app.

The Nest app lets you know if there’s a problem during Nest thermostat setup. You’ll find a number that will tell you what the specific problem is. You can tap the learn more button on the screen for some basic troubleshooting advice.

Tip: Before you start, make sure you have the latest version of the Nest app on your phone or tablet. You can download it from the Apple App Store or Google Play.

Troubleshooting steps

TD003

The TD003 (0.25) error can occur when you haven’t completed language and equipment setup on the thermostat. To fix this error, use the thermostat screen to continue setup.

TD004

The TD004 error can occur when your thermostat goes to sleep before you finish adding it to your account in the Nest app. Follow the troubleshooting steps below.

On the thermostat screen, select Learn more Reset device.
Note: This will not reset your device to factory defaults. This will only reset your account info on the thermostat.
Once your thermostat is done restarting, resume setup in the Nest app.
Tip: To keep your thermostat awake while you add it to your account, press the screen every 20 seconds.

TD009

The TD009 error can occur during the final step of adding your Nest thermostat to the Nest app. Follow the troubleshooting steps below.

1. Check the Nest service status

First, check the Nest support website to know if there's a service interruption. If there's a problem, wait until the service returns to normal to add your Nest thermostat to the Nest app.

2. Reset the thermostat and restart the Nest app

If there isn’t a service interruption, follow these steps to give Nest thermostat and the Nest app a fresh start.

On the thermostat screen, select Learn more Reset device.
Note: This will not reset your device to factory defaults.This will only reset your account info on the thermostat.
Quit and restart the Nest app on your mobile device.
- For iOS devices, follow these instructions.
- For Android devices, tap the Recents button, then swipe the Nest app icon until it disappears. Specific steps for your Android device may vary, so check the manufacturer's website or manual for instructions.
Restart thermostat setup in the Nest app.
If the previous steps don't work, you may need to restart your phone or tablet.

TD018

The TD018 error can occur when the assisting device your thermostat uses to communicate within a thread network is too far away. Follow the troubleshooting steps below.

On your phone screen, the TD018 error may appear. Tap Done to exit setup in the Nest app.
On the thermostat screen, “Your thermostat couldn’t be added to your account,” may appear. Select Learn more Reset device.
Note: This will not reset your device to factory defaults. This will only reset your account info on the thermostat.
Quit and restart the Nest app on your phone.
Once your thermostat finishes restarting, select Nest app on its screen to continue.
Reopen the Nest app and restart adding your Nest thermostat. The Nest app will show you a picture of the assisting device during setup.
Scan your thermostat’s QR code.
Once the entry key appears on the thermostat screen, you must turn off the power to the HVAC system.
Detach the device display from its backplate.
Move the detached display closer to the assisting device.
Press Next on the Nest app to continue.
After the device is added to your account in the Nest app, you can reattach the display to the backplate and turn on power to the HVAC system.

TD023

The TD023 error can occur when your thermostat is unable to connect to your phone or tablet over Bluetooth Low Energy (BLE). This can happen because:

Your thermostat isn’t powered on.
Your thermostat is outside of Bluetooth range.
Your thermostat is already added to another account.

Follow the troubleshooting steps below.

Make sure that the thermostat is powered on.
Move your phone closer to the thermostat.
Reset the account connection on your thermostat. Note: Reset of account connection varies on different thermostat models. Make sure to do a reset connection, and not perform a factory reset of your device.

TD027 and TD028

You may see these codes when there has been a change in your Wi-Fi network.

Check that your thermostat is awake by pressing the thermostat’s ring.
Restart any other Google Nest devices set up in your home.
- Google Nest Camera or doorbell
- Google Nest Nest Protect
  - Note: You’ll need to reset your Nest Protect and add it back to the app.
- Google Nest speakers and displays
- Google Nest Thermostats
- Google Nest Wi-Fi
- Google Nest x Yale Lock

TD030

The TD030 error can occur because:

The assisting device your thermostat uses to communicate within a thread network is powered off.
Your phone and the assisting device are on two different Wi-Fi networks.

To check that the assisting device is working correctly, follow the troubleshooting steps below.

Make sure that the assisting device is powered on. If it isn’t, charge it or connect it to a working power source.
If the assisting device isn’t in use, remove it from the Nest app.
If you have more than one Wi-Fi network, you may have to move your phone to the same network the assisting device uses.

Advanced troubleshooting steps

1. Check your router's Multicast settings and documentation

If your router is supported by Nest thermostat, you'll need to check your router's configuration to make sure that Multicast is enabled for all devices on your network.

If Multicast is fully enabled, refer to your router's documentation to check if it supports Multicast on internal networks, which is required for Nest thermostat. While most recently manufactured routers support Multicast for external connections to the Internet, some may not support Multicast between devices on your home network. If not, try an alternate router that has full Multicast support to know if this resolves the Nest thermostat connection problem.

2. Check the firmware version of your Wi-Fi router

Check your router's firmware version and compare it to the most recent firmware posted on the manufacturer's website. If it's not up-to-date, download the latest version and follow the installation instructions. Your router may also have an automatic update feature. Refer to your router's documentation to check if this feature is available. If it is, you must enable it to ensure you always have the latest firmware.

3. Remove and replace open source firmware

Open source or third-party firmware such as DD-WRT, OpenWRT and Tomato can be installed to enable extra features on certain routers. However, open source firmware is not supported by Nest thermostat. While some versions may work, compatibility may vary from release to release.

If you're using third-party firmware, it's recommended that you uninstall it and update to the latest firmware available directly from the manufacturer. Get specific instructions from the firmware source to uninstall it, and refer to your access point's manual for instructions on how to install and update the original firmware.

4. Reset Nest thermostat to defaults

If nothing else has helped, as a last resort, you can reset your Nest thermostat and restart setup from the beginning. When you reset your Nest thermostat, all saved settings and information will be erased.

Reset the Nest thermostat and erase all your personal settings

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