I've got no dial tone on my phone, but broadband works fine.
If i plug the phone in without a filter.. it knocks the internet off, if i plug into the filter and ring my home number from my mobile, the home phone rings, but when i pick up it's dead, the mobile phone is still ringing, and when i put the home phone down, the handset continues to ring.
I've tried two corded phones with the same result, and verified the phones are working at a different property.
I have been told to plug the phone into the master socket... which I don't have access to. This is a new build house and all that we have is the BT External Master Socket outside the house, as seen here.