AMERICAN STANDARD WATER HEATERS ENS40L-*

The figure of 2,439 kWh is not a registry value. This site computed it from the registry's UEF, the ratio of hot water delivered to energy used, of 0.92, and the DOE test's daily hot-water draw for the low draw pattern. The source is DOE CCD, retrieved 2026-09-19. The comparison group is the 163 models registered as an electric tank at the low draw pattern. Its rank is 19th lowest energy use of 163, which places it in the lowest quarter of its class. The class median is 2,439 kWh, so the difference from the median is 0 kWh. The rank and the median both come from the same class list; the individual values of the other models are not shown here.

The 2,439 kWh figure applies only to the low draw pattern, which represents a one- or two-person household. For that household the unit has a rated volume of 36 gallons and a first hour rating, the gallons of hot water available in the first hour from a full tank, of 46 gallons. For a household with a higher daily draw, this figure does not apply. Energy use at other draw patterns is not available for this model on this page, and it is not estimated here. To compare units by fuel, space and size, use the water heater selector. To look for a unit in the same class as this model, use the replacement search by model number.

Running cost is not written as an amount in this text, because it depends on your own utility electricity tariff. The energy figure of 2,439 kWh at the low draw pattern is the quantity that your rate per kilowatt-hour is applied to. The cost calculator for your ZIP applies your rate to that figure. The page on how the annual cost is calculated explains the steps, including the computation this site made from the UEF of 0.92. The modeled installed-cost range appears in its own block on the page with its source and date. It is a modeled range, not a quote, and it is not repeated here. The energy figure reflects the data as retrieved on 2026-09-19.