See my reply to Zarjaz about that cable between the two rooms. Two extracts from my longer version:-
That cable to the lounge may be ordinary electrical wire or simple telephone wire. Neither is to be recommended. They will work but could be adding noise even now. VDSL2 (FTTC) is much more sensitive to that than ADSLx.
When you say "over an extended distance" in the lounge, do you mean there is a further length of extension cable in there? That is not good. Particularly if it is telephone wire.
The most important question isn't there however. It is as I asked you previously.
Please can you check on Monday if there are any other sockets anywhere in the house. And!
That pictured socket may or may not actually be the master, in my opinion. Please carefully remove that faceplate, which may have wires attached, and see what those attached wires are if any. (Colours and terminal numbers for each).
Importantly, take a look at this page
. (There used to be a far better one but this will do for now). Scroll down to "Making the connections", where there are some pictures. The right hand two are an LJ2/1A. The cylindrical capacitor at the top is what tells the layman like us that it is a master socket, not an extension.
Your Dad's may or may not have the same layout, but if it is a master there will be such a capacitor somewhere there. If there isn't, it is an extension.
Don't worry too much, as Vodafone said, it will work. But I don't like the look of things for the stability, and you don't have a socket in that picture which will take any suitable faceplate
My broadband basic info/help site - www.robertos.me.uk.
Domains, site and mail hosting - Tsohost
Connection - AAISP Home::1 80/20. 200GB. Sync 71357/13895Kbps @ 600m. BQMs - IPv4