I feel your pain Eddy, I'm having the same issues although not as bad as yours yet.
Mine only started 2 months ago, it was working fine until then, then bang....the wi-fi has been up and down like a brides nightie since!
I've just tried the silent line test, should that be totally silent?
It sounds as though there is some static on the line, mine isn't totally silent.
Do BT turn the strength of the signal down during the day?
I'm off work this week and BT are on my list of stuff to sort out.
Whilst we're on the subject, how far can a signal travel?
I live in a bungalow and the BT Infinity 2 signal won't reach my bedroom about 12 feet away! Consequently I'm always paying extra for data useage on my bill
I'm in a similar position to you re the champions league, if the signal drops out tonight, then BT are history, they can come and take the lot out.
Just so that you are aware, the wireless signal is transmitted from your BT Homehub. It does not come down your phone line or through the air from BT.
BT have no control over your wireless signal from the Homehub so can not "turn it down" during the day.
It is not the "BT Infinity 2 signal won't reach my bedroom about 12 feet away!" it is the wireless signal that won't reach.
Your phone line should have no noise when you do the silent line test. If you have static on the line this will affect your broadband traveling along the line to your Homehub.
You need to contact BT and report a telephone fault regarding noise on the line. Once that fault has been resolved your broadband should improve.
Before reporting the fault you should carry out the test again but this time use the test socket on your master socket. If the noise is still there, report the fault. If the noise has gone it means the fault is with your internal wiring or the master socket face plate.
When you connect to the test socket make sure that any phone extensions you have do not have a dial tone. If they do it means you have "star wiring" and that is not good for your broadband connection.