Faulty MCB. Problem isolating ring final circuit at CU with MCB

[maxeon]

I am planning to move a socket outlet. The CU is largely unlabelled so don't know which 32 MCB to switch off. There are 2 x 32a MCB. All other mcbs are for lights (6a) and a dedicated immersion (16a).
To isolate the circuit, I tried switching off the first of the two 32a mcb which isolated some of the sockets but not the one I need to move. So I switched the 2nd 32a mcb off too (so now all/both 32a MCBs off but some of sockets still live.
So I tested RCD and main switch which tripped all sockets other circuits off.
I am assuming there is no cross over of ring circuits and that the 2nd circuit is not picking up a live from elsewhere (heavens forbid) although I then switched off all MCBs on all circuits and the 2nd 32a circuit was still live.
Can I conclude that the 2nd MCB is faulty and so not switching off and needs replacing or is there any other possible cause?
I'm an amateur so please bear with me and this is my 1st post.

 

[Pete999]

Imagine it was common to have three phase boards in Domestic houses...... you would see the black smoke for miles after the cowboys were let loose

And the Paramedics

 

[Specialist]

Morning Pete

 

[Pete999]

Morning Pete

Mornin Andy, how's things?

 

[Specialist]

Sorry Pete, aye I'm not too bad thanks buddy, everything good with you ?.

 

[buzzlightyear]

Imagine it was common to have three phase boards in Domestic houses

not see yet, on any old houses or new!

 

[mrloy99]

I am planning to move a socket outlet. The CU is largely unlabelled so don't know which 32 MCB to switch off. There are 2 x 32a MCB. All other mcbs are for lights (6a) and a dedicated immersion (16a).
To isolate the circuit, I tried switching off the first of the two 32a mcb which isolated some of the sockets but not the one I need to move. So I switched the 2nd 32a mcb off too (so now all/both 32a MCBs off but some of sockets still live.
So I tested RCD and main switch which tripped all sockets other circuits off.
I am assuming there is no cross over of ring circuits and that the 2nd circuit is not picking up a live from elsewhere (heavens forbid) although I then switched off all MCBs on all circuits and the 2nd 32a circuit was still live.
Can I conclude that the 2nd MCB is faulty and so not switching off and needs replacing or is there any other possible cause?
I'm an amateur so please bear with me and this is my 1st post.

Is it a flat?Did the main switch isolate your mystery socket?..Have you been unknowingly shareing with a neighbour.Try...main switch off..if all dead swop the 2 mcbs.And see if the same problem breaker is still passing through a voltage while switched off..Could the immerson circuit and a ring leg be mixed up.