I agree with Greg.
It's just a bit more than 111 Amps at 240V.
The reason that the instantaneous water heater does what it does is because it throws enough energy into the water to heat it up as it's passing through the unit, whereas the 'regular' water heaters take anything up to an hour to slowly heat the water up.
I don't find them to take any more energy in the long run, but MAN do they want a lot of it all at once!
