In addition, tank less water heaters are more efficient at transferring heat from the burner to the water, which can save up to 15% of energy. This is because tank less water heaters use a heat exchanger to transfer heat from the burner to the water, while traditional tank water heaters use a heating element that is immersed in the water.
Finally, tank less water heaters can save energy by reducing the amount of hot water that is wasted. This is because tank less water heaters only heat the water that is needed, so there is no need to drain the tank to remove cold water that has been sitting in the tank.