Are you a Plusnet customer with Wi-Fi issues? Get them resolved by The Phone Fixer, supporting homes and small businesses in Brereton Green have you got black spots in your property?
I try to describe wifi as throwing a stone into a rock pool, the further the ripples go the smaller and weaker they get and if the hit object when strong they can get around them but are drastically weakened. So the further you are from you router the weaker the signal and the walls and ceilings will dampen your signal.