Had a call out on Sunday. RCD kept tripping (upfront RCD) so no power to any circuits. Asked them to try all circuits off and then try each circuit one by one to see which caused the trip whilst on the phone. However even with everything off the RCD wouldn't stay on. So either a faulty RCD (not impossible as an old board) or a N-E fault (more likely). So off I went.
Found the issue was the downstairs socket circuit and as no electrical work has been done for about 4yrs I started taking off sockets in the most recent area, which was the kitchen. IR test was showing a dead short N-E (which was already obvious given the RCD would not stay on as soon as the neutral to this circuit was connected)
Found this cracking kitchen fitters install, particularly impressed with the twist in the conductors as they have rotated the socket a couple of times. There is a feed taken from this socket to a socket under the sink for the dishwasher, all just ran loose on the floor, it was then linked through via the wagobox into a socket in the dining room.
I disconnected this lot yet the RCD still wouldn't turn on. So a bit of head scratching and then I started taking off the socket fronts of all the other sockets on the circuit (17 in all).
I then found this in a socket in the lounge at the opposite end of the house to the kitchen.
It was an incredible coincidence that this and the kitchen fitter special caused a fault at the same time. The lounge socket was causing an issue with the neutral touching the back box. But even when that was sorted I still had a fault. Disconnected the kitchen special and circuit remained energised. Repaired the damaged neutral sleeving with a couple of layers of heat shrink. Also reterminated the live. There is a dead short N-E fault on the kitchen special wiring which I am guessing is behind the cabinet somewhere and has developed over time to the point it now links N-E.
Kitchen is getting a refurb in a couple of months so that's bonus as they now want me to do the electrical work for it.