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Run into this today at a house my nephew is moving into....
Original Dolphin 860 Shower (8600W) installed on 6mm Twin and Earth - maybe 15m length from the CU, which is an old MK board installed in 1986, but RCD protected - on a 45A MCB.
So far so 'normal'....
However, there is 2.5 T&E fed from the positive side of the valve, which feeds a pump in a cupboard above (via a FCU).
They'd purchased a 9.5kW (@240) replacement, which I wasn't comfortable installing on 6mm cable given that the route is unclear - though mostly between floors I think , but the last part of it is in trunking down the wall to the fitting itself...
The pump is slightly throwing me too - it's clearly an old pump that works when turned on, so was fed from effectively a 'switched live' in the shower - fused with a glass fuse in the shower (FCU before pump above).
Is is possible/compliant to do this in any modern shower? Obviously many of them have electronic internals now anyway, so not always clear where a suitable feed could be taken.
Since there is a toilet next door with sink, which has hot water fed from a boiler, I suggested that they get a plumber to put a normal shower in instead....
Otherwise, It would seem that the way to do it properly now would involve changing the pump to one that has a trigger sensor?
On 6mm of 15-20m, I reckon they'd need 7.5kW (@240) - and that I should probably reduce the MCB to 30A (Old MK 3871 Type 2 board). Having said that, there is no obvious overload of the existing cable, which has been in since 1986 by the looks of it....
Does that sound right, or am I missing an obvious answer that is commonly done? Anyone replaced one of these in a similar situation?
Original Dolphin 860 Shower (8600W) installed on 6mm Twin and Earth - maybe 15m length from the CU, which is an old MK board installed in 1986, but RCD protected - on a 45A MCB.
So far so 'normal'....
However, there is 2.5 T&E fed from the positive side of the valve, which feeds a pump in a cupboard above (via a FCU).
They'd purchased a 9.5kW (@240) replacement, which I wasn't comfortable installing on 6mm cable given that the route is unclear - though mostly between floors I think , but the last part of it is in trunking down the wall to the fitting itself...
The pump is slightly throwing me too - it's clearly an old pump that works when turned on, so was fed from effectively a 'switched live' in the shower - fused with a glass fuse in the shower (FCU before pump above).
Is is possible/compliant to do this in any modern shower? Obviously many of them have electronic internals now anyway, so not always clear where a suitable feed could be taken.
Since there is a toilet next door with sink, which has hot water fed from a boiler, I suggested that they get a plumber to put a normal shower in instead....
Otherwise, It would seem that the way to do it properly now would involve changing the pump to one that has a trigger sensor?
On 6mm of 15-20m, I reckon they'd need 7.5kW (@240) - and that I should probably reduce the MCB to 30A (Old MK 3871 Type 2 board). Having said that, there is no obvious overload of the existing cable, which has been in since 1986 by the looks of it....
Does that sound right, or am I missing an obvious answer that is commonly done? Anyone replaced one of these in a similar situation?
