Reservoir N51

This site computed the 1,405 kWh figure; the registry does not list it. It combines the model's registered UEF, the ratio of hot water delivered to energy used, with the DOE test's daily hot-water draw for the high draw pattern. For this unit the UEF is 3.53, taken from the DOE CCD on 2026-09-19. Among the 194 electric tank models registered at the high draw pattern, it ranks 118th for lowest energy use. That puts it in the second-highest quarter of its class for energy use. The 99 kWh gap above the class median applies only at the test's daily draw. The data gives no gap for any other level of use.

The high draw pattern describes a larger household, or one where showers and laundry overlap. This unit's first hour rating, the gallons of hot water available in the first hour from a full tank, is 75 gallons. Its rated volume is 47 gallons. Both figures come from the registry listing for N51. A household that uses less hot water than the high draw pattern assumes will not use 1,405 kWh a year. The data has no figure for a lighter draw, so that lower amount is not available here. To compare this unit with another model registered at the same draw pattern, you can find a same-class replacement by model number.

Running cost is not given in this text because it depends on your own utility electricity tariff. The page works it out from your ZIP code. You can run the cost calculator on your own ZIP to see the figure for 1,405 kWh a year. The method, including the daily draw used for the high draw pattern, is set out in how the annual cost is calculated. The 99 kWh gap above the 1,306 kWh class median is extra energy that would be billed at your own rate. The installed price range appears in its own block with its source and date. It is a modeled installed-cost range, not a quote.