Thanks for your reply Chris. So you dont think its an issue for the DNO ? Just adding the rod back to the MET did not lower, I guessed the utilities underground were also bringing that to the system to some extent so not too suprised. So you think removing the PME and changing to TT system? That did reduce the voltage to 1.2 vdc.
Well your dropping 15 volts, now how much of that 15v is dropped across the supply neutral.
If you have a weak tnc-s say a L - N loop of .0.6 ohms, .3 supply line .3 cne/pen, if we apply 35 amps we would get a volt drop across the neutral of around 10 v.
Your volt drop of 15v suggest a higher loop than the .2 measured.
Well you need to bare in mind two things, one you obviously want to remove the tingling sensation and secondly you need to consider the risk in that location due to a broken PEN.
If you have hit 40 ohms Ra will relative ease you could go down the additional electrode route, getting the Ra down to 2 ohms would reduce the sensation and limit touch voltage to around 50 V.
You could isolate the metal work in the location say by using plastic plumbing.
Or you could TT the installation which remove the link to the neutral.
By all means ring the dno, if a fault exists on the neutral supply this may increase the volts dropped and increase the sensation, though the fact that you have felt the sensation highlights the fact that the locations floor is earthy.
Regards Chris