new tenant, half working installation, BT to fix for free?

Hi all, hoping someone could provide some sane advice

Just moved into a flat and got my BT contract transferred to the new address. Landline gets activated last Friday and everything is supposed to work... except it wouldn't... my phones were mute at any socket - no dialtone, nothing. Yesterday just before calling in an engineer I tried again and it worked in a few sockets, not the important ones (office).

This is an old installation which seems to have been modified multiple times. The outside black cable comes into a junction box from which two cables come out: one into an NTE5 master (with the 'T' symbol) the other dissapears into the wall.

The NTE5 socket has a good line and if I remove the faceplate, the other working extensions stop working, so that makes sense. I have no idea where the other cable ends up, but I'm guessing the remaining non-working sockets (in some sort of a star layout), but I can't verify without opening the master BT junction box (the one with the black cable) which I reckon I'm not allowed to.

Some of the non-working sockets are marked with BT symbols, making me think they're official at the same time that some other BT marked sockets are working. I have no idea of what was done to the installation in the past but I would certainly like to have all BT extensions working, and ideally filtering out the DSL signal into one of the branches (voice only).

My question is: Does this entitle me to a free repair, including tidying up of the master/main connection into a single filtered NTE5?

Thanks all in advance,
Pedro.

Normally BT are only reposible upto the Master Socket. Nothing should be hard wired into the master socket other than the BT line

It sounds as if the previous owner installed all the extensions. If you have a good libe with all the extensions disconnect that implies there are problems with the extensions

I would suspect that BT would charge you for any work on the extensions and that could be costly

Seconded. I have working dialing tone at the NTE, then that's the end of Openreach's responsibility. You can ask your voice provider to have them come out and work on extension wiring, it'll be at your expense.

The chances are the other non-working sockets may have been from a previous owners 2nd line.