Problem with extension phone socket after install

[#1]

Hi there,
Been trawling the place looking to find out how this works but my new fibre installation has left me confused.
I have recently moved in to a new flat and had Plusnet Fibre installed.
The BT engineer installed the new master socket and ran the data extension for the router all ok - working perfectly.
What I completely forgot to ask the engineer about was the secondary phone socket that is present in another room of the flat.
I get no dialtone from this socket. The new master socket is working fine though.
Is this a case of the engineer just not connecting the second socket up? Would I have to remove the master socket from the wall to see if I can actually find the cable for the extension?
Not really too sure how this all works, and how I could wire this up. I'm assuming I would need some sort of engineer to hook this back up.

[#2]

Hi there,
I'd imagine this was disconnected when he fitted the new socket front plate and didn't connect it back up again. It should be possible to reconnect it yourself if you need to (it'll be at your own risk, but there's a few users in here who are pretty good with phone wiring and will no doubt pop in soon), but bear in mind it could add interference to the line - if you have portable phones perhaps you could get away with not having to reconnect it? Just a thought.

[#3]

Ah ok.
Well the main reason for it is to connect the sky box up to the phone line - I imagine at some point they are going to get cranky my sky box cant dial out through the line or whatever funky stuff it needs to do.
So it could add interference to the main line (as in my broadband and normal calls) as well?

[#4]

There's a chance, yes, if the wiring is bad. You'd also need to make sure the sky box was plugged in through a filter as they are (or at least used to be) renowned for causing interference - a filter will prevent this though.

[#5]

The wires that go into the extension faceplate on the master socket are very thin and brittle and it's possible they have dislodged or broken one when they have been fitting the new VDSL plate.
The lower part of the socket has been designed for the home user to connect their extensions into - any chance of a picture of it and I can possibly help further. As a minimum, pins 2 and 5  on the master socket need to be connected to pins 2 and 5 on the extension socket