A. O. SMITH GCF-50 1**

The figure of 245 therms is computed by this site, not by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the DOE test's daily draw for this pattern. This model's UEF is 0.69. The figure is for natural gas only. It is not a metered reading from a home, and actual use depends on that home's own hot-water use, which is not in the data. The DOE CCD data was retrieved on 2026-09-19. The method behind the annual figure is on the methodology page.

This model ranks 130th lowest in energy use among the 414 models in its class. That places it in the second-lowest quarter for energy use. The class median is 260 therms, and this model sits 15 therms below it. The comparison holds only at the high draw pattern, which describes a larger household, or one where showers and laundry overlap. The first hour rating, the gallons of hot water available in the first hour from a full tank, is 84 gallons. The rated volume is 48 gallons. A household with lower or higher use than the test's draw will see different energy use. For a different fuel, space or size, use the water heater selector.

Running cost is not stated here because it depends on the state average residential gas price. The cost calculator on your own ZIP applies that price to the 245 therms figure. The cost it returns is for the high draw pattern only, so a household with different use should treat it as a reference point, not a forecast. The installed price range appears in its own block, with its source and date. It is a modeled installed-cost range, not a quote. To compare a same-class unit against GCF-50 1**, find a replacement by model number and check it against the 260 therms class median.