Unbelievable, I was called out this morning to a home with reported no power at sockets. A this home I had previously found faults before that were caused by poor workmanship (see post #1517) by others before me. On the way I was wondering if it was something I had done. The problem reported was an RCD covering 9 circuits would not stay in, sometimes. The first problem I had was the neutrals and earths were not in the correct terminations in the CU busbars, and because it was a busy dual tariff board it took about an hour to sort that out and trace the problem to a circuit labeled "panel heaters". I completely isolated the circuit wiring and put the power back on to stop for a cup of tea. But no power still on the ring. After poking around with the voltage tester I found there was no connection across the neutral pole of the RCD. Closer inspection resulted in the neutral input wire falling out of the RCD, the screw had not ever been tightened! It was held firmly in place by the pressure of the cable coming through a tight bend on the approach. Then still problems because the CU was one of those push onto busbar Quickline models and the RCD had now pulled off the busbar at the top and it was a right fiddle to get it to fit securely. Finally got the cup of tea and then decided to trace the problem on the panel heater circuit. Switched off both panel heaters, still a fault. Pulled the covers off the panel heater SF spurs and to my surprise found the wiring live (with voltage tester). But I had wiring for the circuit at CU completely disconnected. Discovered the labels were incorrect on the CU (doh). A few minutes later I had worked out it was a neutral earth fault on a day rate Immersion water heater circuit, not panel heater circuit. Whoever refitted a 2nd bathroom with a new shower had inserted a new MCB in slot 2 and moved all the circuits along one without changing the labels, compounded by the fact the labels were incorrect at the time of the shift anyway. So me thinks no problem, the customer can use the off peak for water heating for now until sort the Immersion in slower time. But no, they had canceled the eco7 on the metered supply. I now have an immersion heater change job tomorrow morning :-( wish me luck with unscrewing it.