Guys was called out last week to a 2nd floor flat British Gas was to have moved the gas meter but refused because the fitter checked the gas meter pipework with a volt stick and it lit up. He added that it could be nothing but he could go no further until it was checked out .
Had a look it was a split CU one side RCD and non RCC
Supply was a TNCS (Ze=0.06)
Gas pipe bonded with a 10mm
Water pipe bonded by a 10mm
I checked this out and measured for voltage at the meter via a separate earth and nothing and yep volt stick lit up I eventually tracked the problem down to the central heating boiler but went no further as it is under a maintenance contract .
So I take it this can be common on a TNCS or PME supply in a flat ? Anybody had this and what checks do you do ie amp probe the gas pipework and any faults that you have found causing this