I got an iPhone 6 a little over a month ago. I had no problems connecting to Wi-Fi anywhere (school, home etc). As of two weeks ago or so, the Wi-Fi 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 Wi-Fi! 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 Wi-Fi 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.