A. O. SMITH HETF-55 1**

The figure of 5,278 kWh is calculated by this site, not published by the registry. It starts from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.94. The site applies it to the daily hot-water draw the DOE test sets for the high draw pattern. The fuel is electricity, and the source is DOE CCD, retrieved 2026-09-19. Among the 194 electric tank models registered at this draw pattern, the model ranks 172nd lowest for energy use, which puts it in the highest quarter of its class for energy use. The figure describes the test draw only. Use in a specific home is not available here.

The first hour rating, the gallons of hot water available in the first hour from a full tank, is 75 gallons on a rated volume of 55 gallons. These figures describe capacity for the household the high draw pattern represents: a larger one, or one where showers and laundry overlap. For that household, the model uses 5,278 kWh a year at the test draw. A reader who compares models mainly by low electricity use should note the 172nd lowest position among 194. The water heater selector filters by fuel, space and size, and the same-class replacement finder works from a model number. The registry data used here does not say whether 75 gallons meets a given household's peak demand.

Running cost is not written as an amount in this text because it depends on the electricity tariff of the reader's own utility. The cost calculator applies the rate for the reader's ZIP to the 5,278 kWh shown for the high draw pattern. The annual cost methodology explains how that calculation is done. The gap of 3,972 kWh from the class median of 1,306 kWh is also a difference in energy, so the same rate turns it into a cost difference. The modeled installed-cost range appears in its own block with its source and date, and this text does not restate it.