Confirm your Honeywell thermostat model supports WiFi
Install the Honeywell Home or Resideo app on your phone
Create or sign in to your account
Make sure your phone is connected to your home WiFi network
Turn on the thermostat and open its menu
Select WiFi setup or network setup on the thermostat
Put the thermostat into WiFi setup mode
On the app, choose Add Device or Add Thermostat
Follow the app prompts to scan or enter the thermostat code
Select your home WiFi network
Enter the WiFi password
Wait for the thermostat to connect
Confirm the connection on the thermostat and in the app
Test remote access by changing a setting in the app
If needed, restart the thermostat and router and try again