It is a conventional 2-way circuit
There is a feed to the common terminal of the first switch,then a pair of strappers to the second switch, with the switch live to the light from the common of the second switch.

The 2-core 3-core method that you use, used to be called a conversion circuit


Just seen this info in your post
That Fault was that the lights would NOT go off

For the light to be permanently on there would have to be 2 faulty 2-way switches both staying in one position only
That would be a very remote possibility

Trace the live feed through the switches and check their function of switching the live from L1 to L2

themethod you see is often used in conduit/trunking systems.

I replaced both switches to rule out this ...... IS THE WIRING DIAGRAM CORRECT IT LOOKS FINE TO ME ,

This is an old method of wiring in singles within a house ?

Des 56 said:

It is a conventional 2-way circuit
There is a feed to the common terminal of the first switch,then a pair of strappers to the second switch, with the switch live to the light from the common of the second switch.

The 2-core 3-core method that you use, used to be called a conversion circuit





Just seen this info in your post
That Fault was that the lights would NOT go off

For the light to be permanently on there would have to be 2 faulty 2-way switches both staying in one position only
That would be a very remote possibility

Trace the live feed through the switches and check their function of switching the live from L1 to L2

Click to expand...

You must have the feed of the first switch connected to the wrong connection at that switch
The feed is probably on one leg of the strappers instead of at the common,this will permit the 2nd switch to act as a 1-way and the 1st switch to keep a feed on the switch wire to the light on permanantly (when in the one particular position)

As I said in the first reply,check which is the supply live and follow it through the switching as in the diagram and YES it is a correct wiring method for a 2-way
Just follow your switching route and you will get there

Your diagrams are quite small so I am not sure but it looks like in your diagram you have L1 connected to L2 on the other switch and L2 connected to L1 on the other switch. the conventional method would be L1 to L1 and L2 to L2 not that that would cause the fault just odd, but functional.

Have you tried doing a continuity test on the switches to check their function, I know you have changed the switches but sometimes the basic way is the easy way.
From what you have described the only fault can be a permanent on state from C to L2; but you have changed the switches?
Where is the permanent line fed from is this from the 3plate at the light and is there any link/ short in the plate.
This is a modified diagram of 2 wire 2 way wiring to compare with your set up, I have shown neutral fed to the switches for convenience of using T&E but this does not have to be the case when wired in singles.

with two way lighting it doesnt matter if the strappers are crossed, it matters that the common is in the right place.

Domestic ...............................look out for the borrowed neutral on this one