Please try to search for the Wi-Fi network one more time.
If that doesn't work you may have a hidden network and in that case please consult the manual of your Wi-Fi router to find out if your Wi-Fi network is hidden (SSID Broadcast disabled) and how to make your Wi-Fi network visible (SSID Broadcast enabled).
Once you have completed this step you can connect the DEVIreg™ Smart to your Wi-Fi as described in this article: How do I add the DEVI Smart App to my DEVIreg™ Smart thermostat?
When the DEVIreg™ Smart thermostat is connected to your Wi-Fi you can afterwards hide your Wi-Fi network again if needed by consulting the manual of your Wi-Fi router.
If you are unsure on how to configure your Wi-Fi router we recommend you contact the provider of your router.
The Wi-Fi network may not be shown due to the chosen frequency on the Wi-Fi router.
The DEVIreg™ Smart thermostat supports Wi-Fi routers with 2.4 GHz frequency. Most Wi-Fi routers that support 5 GHz also support 2.4 GHz by default to ensure the widest compatibility with Wi-Fi products. Please consult the manual of your router to learn more about what frequencies it can support.