Timed out repeatedly

We use our Roku streamer to watch tv for about 2 hours each night. It went kaflooey.  I bought a replacement.  We watch tv in the living room and the router and modem are in the office, not close by.  I have tried umpteen times to get the replacement to pick up the wi-fi signal but it doesn't.  I blame the influx of tourists using their phones to stay in touch with friends.  The whole deal is a rigorous challenge to one's patience.