If the wifi light on your Classe 300EOS with Netatmo is flashing red, this means that there are problems connecting to the WiFi network. The connected function of the Classe 300EOS with Netatmo is activated but is not connected to your WiFi network. Check that your modem is powered on. Has someone changed an access password on your home WiFi network? See FAQ: How do I restore the WiFi network on my connected Classe 100X?