HomeEXCEPT's gateway is designed to plug into your internet router and work with no other configuration required. Consider the following before troubleshooting the gateway.
Change the sensors to your own city. Bring the sensors next to the gateway. Check the last data date and time on the sensor list view. If it is the current time you are connected. You can now set notifications and the graphs will begin showing data in approximately 20 minutes.
If last data is not current it is possible there are some custom settings on your router that are preventing the connection. The following questions will help us troubleshoot for you.