Is there a way to extend my Lyric's WiFi signal strength?

The range or distance of the WiFi signal is determined by your router. Check your router's manual for additional information. It is possible that your thermostat is unable to find or maintain reliable connectivity to your WiFi network because of a poor signal from the router. For example, most homes have “dead spots” where WiFi signals are unreliable. This can be fixed by moving your router to a better location or by setting up a repeater- a device that will pick up and rebroadcast the wireless signal from your router to your thermostat. You can either purchase and install a WiFi repeater, or configure an additional router to serve as a repeater. Most standard routers can be configured as a repeater.