Your ecobee3 lite may have lost its Wi-Fi connection to your router and that connection needs to be refreshed.
NOTE: If you're connecting your ecobee3 lite for the first time, the Installation article can help. If you have a new router or changed your Wi-Fi password, the Update Network article will help you reconnect.
1. Check the your router to make sure it is on and that you can connect to the internet with other devices. If you can connected to the internet on other devices, proceed to Step 2. If you cannot connect, try restarting the router by unplugging it. After restarting the router if you still cannot connect on any device call your Internet Service Provider (ISP).
2. The thermostat should be restarted. It can be turned off by pulling it from its wall mount or by setting the breakers to off for the heating and cooling system.
3. Keep the thermostat powered off for a minute then and power the thermostat back on by either putting it back on the wall or by resetting the breakers, depending on how it was turned off. Allow the thermostat to complete its boot up process.
4. From the Home screen, open the Quick Changes menu by tapping the cog icon in the bottom right of the screen. In the upper right corner of the Quick Changes menu there is the Wi-Fi connection icon.
This icon will show the status of the thermostat's connection to your router and to ecobee.com (see description below). The thermostat may still be trying to reconnect and the icon may be a red smart phone with white Wi-Fi bars - close the Quick Changes menu and wait another minute to allow the thermostat to connect to ecobee.com.
The icon should change to a white smart phone with white Wi-Fi bars when the thermostat is connected to the internet and ecobee.com. Now, you will be able to connect to your ecobee through the mobile app and the web portal.
For additional support connecting to Wi-Fi, email firstname.lastname@example.org or call 1-877-932-6233. To help our agents resolve the connection issue, have your network information and the make and model of your router available. The Network Information article explains where to find the network information on the ecobee.
When emailing our team for support, include pictures of the "Diagnostics" (Menu>Settings>Wifi>Diagnostics) screens and the make and model of your router.