Once went to a house, new tennant had moved in, had shower installed and first time it was used supply went off. However, supply came back on when shower switched off. The outgoing live terminal in the meter was totally undone, had obviously been like that since meter was installed, as it still had lead seals fitted, which were secure, but we hadn't used them for at least 15 years. Previous tennant only used lights, tv fridge etc, gas cooker, no washer even!