This one need very thick wiring. What model you looking at  is it the 7kw heating element? That take minimal 30amps. Writing is crucial.  If you are running on single phase you risk running your house electrical to the limit.

I seen similar system during homedec, but no experience in it. Was part of my consideration when I renovate my house.

Any reason why you use this and not storage water heater or solar? You still need to use central piping.

actually it is the same thing for storage vs stiebel. Storage heater consumes 3kW while stievel 7kW.

Assuming u r using a 25litres storage heater like JOVEN JH 25. U nd 2 wait 5 minutes for it to boil and you shower 10 minutes. (to make things simple, we assume kW consumption is per minute)

Total kW Consumed (Storage) = 15 x 3 = 45kW

Total kW Consumed (Stiebel) = 10 x 7 = 70kW

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Added on June 13, 2012, 8:48 pmSolar is cheap, RM 3k+ can get one d. It is true u might need to turn on the electricity sometimes but not EVERYDAY. WHen u start using solar, u wont wanna get other type of heaters.

stiebel is a trusted brand from europe. cant go wrong there. but the right question has been asked WHY??

storage is cheaper
solar is cheaper

if you want instant - go for gas (way way cheaper). instant gas heaters work great, have almost zero maintenance and dont consume much gas. why burn gas first to make power, send to your place and then use it to heat up water? cut the middle man

All the arguments are valid. Last year i was building my house and was rally into solar, especially the microsolar water heater. Finally decided for steibel as the initial outlay was much less for 5 toilets, as i need hot water only for shower time, not the kitchen. Doing the maths, I wont use full hot water, just using the mixer to regulate the temperature of the shower and i dint spend much time there, maybe 2-3 minutes? All units are installed just above the ceiling and the copper piping is only 5 to 6 feet long.So far so good, instant hot water....maybe a 5 second lag.
Solar heaters need copper piping, thats  costly if you wanna pipe the whole house and these are in wall pipes, you dont know when or where it can leak.
That my take, it really depends on what you require in your house.