Electric water heaters are not dangerous at all!
Like any other heating device, electrical water heaters also work on the principle of conversion of energy. In this device, electrical energy from the main electrical supply runs through the machine and gets converted to heat energy.
They are fairly simple to use and don't involve any risk factors. However, like most electrical devices, regular maintenance is extremely important for the proper functioning of electric water heaters. Without proper maintenance and repair, there can be a chance of a short circuit that can damage the device!