Heat exchangers are very handy. Harnessing the power of your boiler to heat your domestic hot water is a wonderful option. Water Heaters, Gas or Electric are not all that efficient but definitely have their place. If you need lots of hot water and quick recovery, then an efficient, clean, and slient tri-angle Indirect Water Heater is what you need. They last longer, and are much more efficient than a gas or electric water heater.