I have wi-fi with a repeater in my home. My tablets and laptop work on the wi-fi just fine; anywhere in the house I get good signal. My wife's Galaxy S4, and my LG G2 for that matter, seem to get good wi-fi signal but always seem to want to use the poor 4G signal for internet or facebook. Is there some way to set these phones up to have wi-fi as the preferred signal? Most of our data usage is done in a location that has wi-fi but both these phones seem to always want to use 4G which of course, uses data.