Can you change a 2 gang wall socket to a 3 gang without having to add in more wires?
I am no electrician, but yes. Your ring main circuit will have loads of sockets on it
There should be 2x 2.5mm twin plus earth cables there. That is what the ring main is.
If so, you are fine.
There should be 2x 2.5mm twin plus earth cables there. That is what the ring main is.
If so, you are fine.