Apple TV won’t connect wirelessly to my Telus modem/router. It is up to date, Apple TV 3. It works at my sister’s place so there is nothing wrong with it.
A few more details would be helpful.
Has it worked recently on your router?
Has your wireless password changed recently?
What error message are you getting on the Apple TV when you try to connect to your network?
Have you tried forgetting the network from the Apple TV and reconnecting with your wireless password?
>>> Settings > Network > Wi-Fi > select your current network > select Forget Network