Hi,
Over the weekend I replaced the broken central heating timer at my girlfriends. The next stage is to fix the zone valve in the airing cupboard and, whilst I'm there replace the wiring to the immersion heater as it isn't in the best of conditions and looked a bit old and the cable is tight across from the FCU to the cylinder. The FCU looks a bit old, with curved corners and the switch looks an old design.
I tested for live then isolated the socket circuit (single MCB for all sockets) and retested to make sure they were safe then removed the FCU cover. I was slightly surprised to find that the FCU wasn't off a spur from the power point in the bedroom behind the airing cupboard but was wired into a ring. What was more of a shock was that the earth wasn't the modern single copper but looked like multiple steel wires. The cable insulation hasn't broken down and wasn't brittle (in fact it looked like PVC). After an hour or so of moving furniture and making myself unpopular as whoever had fitted the power points had fillered them in so you had to break a seal round the edges to get into them I have found a power point that has that wiring and have now tested and sadly the suspect wiring is in a ring so I can't just isolate it and provide power from elsewhere. In fact the live/neutral were all
The house was built in 1968 and was supposed to have been rewired. The meter has company seals and documentation from 1990. The company fuse (which was in backwards) doesn't have any seals so presumably the rewire happened after then. The rest of the rewire looks reasonable - expensive MK Sentry non-split box - the only dubious bit being no separate earths to the metal boxes and some of the bend radii in the sockets.
Can anyone identify the cable? Could they have tested it for soundness and not replaced it as it will require a lot of redecoration if they couldn't have pulled it through.
Any ideas? Should I be worried?
Thanks,
Simon