Has anyone got statistics about energy savings after switching to on demand water heater?

I am thinking of getting the Bosch water heater and would like some before and after energy bills or savings information.





Also any problems or drawbacks to on demand water heaters?

Has anyone got statistics about energy savings after switching to on demand water heater?
I don't have any hard numbers, but my inlaws have an on demand system and say there energy has gone down a good deal due to it. Instead of your water heater always running to try to keep a huge tank hot, it only kicks on when you need it.


They've had theres for over 6 years with no problems.