We have put together a short survey to capture your feedback in terms of what BT can do when you experience home Wi-Fi issues. We would appreciate it if you could take a couple of minutes to complete a short survey. Read more from here, Fix my home Wi-Fi
First flush any old invalid DNS entries.
If its a Windows computer you are using, then type this at the command prompt
Is the computer connected to the home hub using wireless or Ethernet connection?
If its wireless, then try using a direct Ethernet cable connection.