Why is my thermostat showing up as offline?

Last updated

If you are unable to complete the setup/connection/registration process, or if your thermostat frequently loses wi-fi connection, attempt the following before reconnecting:

Power cycle the thermostat by removing it from the wall for 30 seconds. Reattach the face plate.

Turn off mobile/ cellular data on your mobile device and connect to your home Wi-Fi network. “Forget” any other Wi-Fi networks in range. (Turning on Airplane mode is also an option)

Some Android phones have an updated security feature that may not allow your phone to connect to “unsecured” Wi-Fi networks. Temporarily disable this feature via Settings – Network & Internet – Wi-Fi – Wi-Fi Preferences on your mobile device.

Attempt to connect and register the thermostat to a mobile hotspot. This allows the registration data to bypass any network security that may be causing the connection failure. Once successfully registered, a Wi-Fi Reset can be performed to move the thermostat to the home Wi-Fi network.

Advanced Steps:

If you experience inability to connect, failure to register, or frequent Wi-Fi signal loss, verify the following:

*You may need assistance from your Internet Service Provider to verify/ change some settings*

  • Setup a 2.4GHz Bandwidth Only network with separate SSID (Not compatible with 5GHz networks. Simultaneous 2.4 and 5GHz networks that share a name or SSID are not recommended and can cause thermostat to lose connectivity). * The T9/T10 thermostats are capable of communicating on a 5Ghz wi-fi network – all other models currently only operate on the 2.4GHz bandwidth*
  • Connect directly to the router signal – Not recommended for use with signal booster, satellites, or extenders.
  • Business Networks (Enterprise networks, guest networks, or networks that require logging in via a web page/portal) are not supported.
  • Gateways or Network switches can block some traffic to Honeywell / Resideo and are not supported.
  • Recommended WPA2-AES Network Security Protocol
  • DHCP Enabled – Static networks not supported
  • UPnP / P2P Enabled
  • Band-Steering Disabled

*"Not Supported" refers to network configurations that may be compatible, but cannot be successfully supported by Resideo Customer Care. "Incompatible" refers to networks / configurations that the thermostat is incapable of communicating with.*

For more information, please watch this instructional video:


Message Resideo


Message us on Twitter for help with our products.

Monday through Friday:
9am to 6pm CDT
Saturday and Sunday:
9am to 5pm CDT

Live Chat with Resideo


Connect with an agent for quick assistance.

Monday through Friday:
9am to 8pm CDT
Saturday and Sunday
9am to 5pm CDT

Call Resideo


Speak directly with an agent for help with our products.