I've just got a shower, its 8.5KW. Our consumer unit is very old, its a MEM Memera21. Currently its got 2x 5A MCBs for lights, 16A for Immersion Heater, 32A for power sockets and 32A for the cooker. The cooker wire goes into a big switch on the wall behind the cooker and inside this theres another wire that goes off in the wall up to the airing cupboard upstairs which is behind where the shower will go, here there is another switch like you'd have for a cooker. So I know the shower should ideally be on a seperate MCB and wire, but I'm wondering if it'd be safe to use this existing wire. It obviously used to be for a shower before we bought the house but no idea what power rating that was. I've seen the maths of 8500W/230v = 36.96A So I think I'll need to change the MCB from 32A to a 40A (or rather I'll be getting an electrician in to swap this). The MCBs already in use are Type1, I've found a Type3 (http://www.reconelectrical.co.uk/index.php?act=viewProd&productId=27527) and I found a TypeB (http://www.neweysonline.co.uk/mem-mcb-memshield-type-b-40a-single-pole-230v-ac/1050072404/ProductInformation.raction) Are these any good for this CU? The only place I've found a Type1 MCB is on ebay for £30+postage, I'm trying to do this a cheaply as possible. Thanks, Brad.