Well, i never really give this topic much thought until today when i heard that my cousin just passed away last night due to electric shock from water heater...

I'm sure almost everyone of us must have at least 1 electric water heater in the house so I'm wondering how safe is the water heater actually?

Isn't the device suppose to have some built in protection?

geessh.... damn scared now....

This is quite misleading.

First, unless it is running off battery, otherwise they will still require AC to DC conversion, which still take in AC from the mains. Therefore anything wrong inside there are possibilities of electrocution.

Secondly, and MOST IMPORTANTLY, most of the electrocution cases are not leakage from the water heater, but from the external sources and KILL THRU WATER HEATER!  Therefore it doesn't matter whether the water heater is powered by AC or DC.