Tankless water heaters, as the name implies, are devices that provide hot water on demand without the use of a storage tank.Tankless water heaters are typically more efficient than conventional water heaters when the hot water per day
usage is around 45 gallons or less. Certainly this level of usage would apply to millions of households in the United States, adding up to a savings of $75-$200 per year over a conventional tank unit,  depending on your individual level of hot water usage. Check out these guidelines to help you decide if going tankless is right for you.