My iphone 5 will not find Wi-Fi?

A week or two ago my iphone 5 stopped picking up my home Wi-Fi or any other Wi-Fi. I went into the genius bar and ofcourse the Wi-Fi worked there but they replaced the phone anyways. So I came home with a new phone excited to have it work again only to find out yet again no Wi-Fi showed up. All the other wireless devices in my house can connect to and find Wi-Fi except for my phone. Does anyone know how I can solve this?

-It didn't only happen at my house with my old phone but I'm not sure if its only happening at home with my new phone

Tell your phone company

I can already tell it is not the phone and they only did it to appease you. Odds are your Wi-Fi settings are incorrect; it's the router not the phone.