Not denying that is in the latest regs under 6.16.2 .My point is that if you were to ask 5 sparkies on how to apply it to an old install(say before 2013) you would get different answers as most would say new geysers must be on earth leakage with own earth leakage.If there is no space in the board and you put the hwc on earth leakage ,good luck going out at night cause house has no power(maybe lights) as earth leakage is tripping due to the hwc being put on it.The company doing the coc will struggle to their reputation back from that .That is my point.