Why am I getting a WiFi Signal Lost message on my VisionPRO (TH8320WF or RTH8580WF) thermostat?

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If you’re getting a WiFi Signal Lost message on your VisionPRO (TH8320WF or RTH8580WF) thermostat, it probably lost internet connection. Please follow the steps below to remedy the issue.


*If your thermostat has lost WiFi connection, you will be required to be on-location with the thermostat to reconnect it manually. For some users, a reconnection may be possible by remotely re-starting your WiFi router. Check with your internet service provider for possible options.*

To reconnect your device to WiFi:

  1. Make sure your router is online.
  2. Go to your thermostat on the wall and remove it from its base.
  3. Wait for 1 minute.
  4. Add the thermostat back to its base on the wall.

If that doesn’t work, try the steps below:

Resetting Thermostat’s WiFi Settings

  1. Press System.
  2. You’ll see 5 blank boxes at the bottom of the screen. Press and hold Middle Box for about 5 seconds to change the screen.
  3. Press the left set of arrows until the first number is 0900.
  4. Press the right set of arrows until the second number is 0.
  5. Press Done at the bottom-left corner.

Reconnecting Thermostat to WiFi

  1. Make sure WiFi Setup is displayed at the top of the screen.
  2. On a mobile device, view the list of available WiFi networks.
  3. Connect to NewThermsotat_[series of numbers/letters]. *This is a wifi connection between your phone and your thermostat – it is normal to receive a message that states "this connection has no access to the internet" – please dismiss the alert and continue. Do not allow the phone to change to another WiFi connection until you have completed step 10.* If you do not see the " NewThermsotat_[series of numbers/letters]" network, remove the thermostat faceplate from the wall for 30 seconds and then reattach it and reattempt.
  4. Wait for your browser to automatically open a setup screen. If this doesn’t happen, open a new browser on your mobile device and go to the web address
  5. Find the name of your home network and press Red Button below it.
  6. Enter your home network’s password and press Connect.

If you’re still having issues, please call Honeywell Customer Care at 1-800-633-3991.

Is it time to upgrade your thermostat? Let us help you make the right choice for you and your home with our thermostat upgrade guide.


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