apple macbook air 13inch early 2014osx yosemite 10.10.4

I have been using the macbook air with my bthome hub for the last 15months without any problem and recently after updating a few of the apps iTunes and a few others my wifi is permanently looking for connection `i have tried splitting the modem broadcast range into two one at 2ghz and one at 5ghz but this has not fixed the problem as always in this case there are two systems involved Apple and BTelecoms getting one to talk to the other is not easy and i Have visited numerous forums and discussions tried varies posts and suggestions to fix this issue but the fault still remains, It is getting to the point where I feel that there must be a simple solution but where is it Apple or BT nobody wants to hold their hand up and resolve this issue please help can you provide apple network settings for a BThome hub 4 please I am also writing this on the bt forum to see if they can give me their apple settings it doesn't help when they don't even have a solver for this version of OS X yet maybe they'll catch up soon. `thank you for your assistance I hope it saves my wifi router from the bin!!!