Socket Testing
How to Test a Pre-Filtered Master Socket (Two-Port Openreach Socket)
A pre-filtered socket has two slots and is tested a little differently to a single socket. This video shows you how to reach the test point behind the faceplate so we can rule out your internal wiring on a fault.
Step by step
- 1Start at your pre-filtered master socket. You'll see it has two slots.
- 2Remove the cable that's currently plugged into the socket.
- 3Press the clips on either side and pull the faceplate away.
- 4Take a filter and connect it to the slot behind the faceplate.
- 5Plug your cable into the slot marked ADSL or modem. That completes the test.
Common questions
How do I know I have a pre-filtered socket?
A pre-filtered socket has two slots on the front. A standard single master socket has one. If yours has one slot, follow our single-socket test guide instead.
Which slot do I plug the cable into?
The slot marked ADSL or modem behind the faceplate, after you've connected the filter. This routes your connection through the test point.
What does this test actually prove?
It connects you at the point before your internal extension wiring. If the fault clears at the test socket, the problem is likely in your own wiring rather than the Openreach line, which tells us where to look.
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