Twenty to 40 percent of an average household heating bill is just for hot water. And that’s just for common household hot water usage, such as laundry, baths and showers, and dishwashing. Most of us rely on a conventional storage water heater, whether it is powered by electricity or gas. It provides all the hot water we need, as long as its size is designed for the number of people in the household. It has a fairly long life, maybe 15-20 years, and when it goes we replace it with another standard …













