I got an iPhone 6 a little over a month ago. I had no problems connecting to wifi anywhere (school, home etc). As of two weeks ago or so, the wifi would drop in and out. This wasn't TOO bad or worrisome because I had the same issue on my Android. It got gradually worse, it would stop working for hours on end. Some day were better than others. As of 2 or 3 days ago, it just stopped working completely. So I went to the router and there, perfect wifi! I walked several feet away and it got weaker and weaker until it stopped by the time I reached my room.
My fine connects and works on WiFi networks just fine anywhere else. We have iPhones, Android's, tablets and a PC that work fine on the home network. I've tried trouble shooting by restarting my phone, turning router on and off, erasing phone network settings, making sure I have latest ios etc.
Read more: I don't get wifi if I step away from router?