BT Master sockets

Generally speaking, over the years there have been various types of BT master sockets installed.
There is a specific style you should have as an end user, for todays technology to work efficiently and have a demarcation point.
This will allow you to verify if you have a fault on your wiring or in the BT network.
However, having the wrong socket fitted and calling Openreach in, to check for a fault can be very costly.

Master sockets in your home

The list below will show one of the sockets you may have installed your premises.
BT master sockets are generally fitted as standard nowadays.

Telephone socket 2/2A, (generally a system socket) compared to a single 3/1A or twin 4/1A faceplate socket.

As a result of having the “small” system socket you have no way of testing the individual line coming into the premise,
if there is extension wiring attached. The picture below shows two cables attached to the 2/2A socket.

One cable is the incoming service from your service provider (the one with black tape).
The other cable is feeding your extension sockets around your house.

Should you experience some type of fault, you only want to test the cable that feeds the socket, (The black tape cable).
You can’t do it. Thus, you have the wrong type of socket installed.

Regardless of the socket being a 2/2A or 3/1A , you cannot disconnect the extension wiring from the circuit.

Consequently, should you get a broadband or telephone line fault, instead of just testing the BT side of the line,
you are testing the house extension wiring, including the BT network wiring.
Specifically, you cannot tell if it’s your house wiring at fault, giving the possibility of an expensive call out charge from Openreach.

A single or twin faceplate socket, likewise, is the same as the small system socket.
Therefore all your wiring will be connected together with no capability of testing the single incoming circuit
without testing your house circuit in tandem.
This is generally the piece of kit an electrician or similar amateur would fit
unaware of the problems they may be causing in the long run

BT master NTE5a

The most common at present, a master socket NTE5a.
If wired correctly, this will disconnect any extension wiring just leaving the incoming line from the BT network attached.
All new installations should have BT master sockets installed.

This has two small screws that undo, allowing you to pull off the front plate.
This actually allows you to test whether your telephone line or broadband is working correctly from the test point inside the socket
as your circuit is now within the limitations of the service provider contract you have agreed to.

With the screws removed you can pull off the face plate, this will reveal another socket within the body of the remaining plate.
This is your “demarcation” point, The point where your service providers commit takes effect.
In most cases, you are responsible for the wiring leaving the faceplate.

BT NTE5a master with VDSL faceplate attached

Similarly you may have the nte5a with a larger cover socket on the front.

The VDSL plate is designed to stop the broadband signal from being transmitted along the extension wiring.
Thus eliminating any possible interference from the cabling, sockets or equipment plugged in to it.
All being well, the broadband signal you receive at the master socket with the VDSL front attached,
should be the best you can achieve.

The latest BT Master socket NTE5c

This has a pull off front, that again if wired correctly, will give you access to a test socket.
Allowing you to test whether your telephone line or broadband is working correctly.

If wired correctly, this will disconnect any extension wiring just leaving the incoming line from the BT network attached.
In contrast to the NTE5a the NTE5c has the same demarcation abilities. Its difference being it has a pull off front and the connections are of a clip down termination, not needing any tools.
Similarly to the NTE5a it also comes with a VDSL front plate allowing the plate to filter the broadband service at source, before it connects to your extension wiring.

It also has clip down terminations & a test socket inside