A. O. SMITH GCR-40 2**

This site computes the figure of 264 therms, not the registry. It combines the registry's UEF with the DOE test's daily hot-water draw for the high draw pattern. UEF, the ratio of hot water delivered to energy used, is 0.64 for this model. The energy source is DOE CCD, retrieved 2026-09-19. The model ranks 236th lowest in energy use among 414 gas tank models at the same draw pattern. That places it in the second-highest quarter of its class for energy use. The difference from the class median is 4 therms, and it is above the median. The figure applies only at the federal test's draw. Actual use in a home will differ, and this page cannot estimate by how much.

The high draw pattern describes a larger household, or one where showers and laundry overlap. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 80 gallons. Its rated volume is 38 gallons. The registry states these values, and the data here does not show whether they cover a particular household. A reader whose use is lower than the high draw pattern should not apply the 264 therms figure directly, because it depends on that draw. To look for energy use below the 260 therms class median, try the water heater selector. You can also find a same-class replacement by model number.

The page does not state a running cost. It depends on the state average residential gas price for your ZIP, and the data here has no such price. Use the cost calculator to apply your own rate to 264 therms at the high draw pattern. Against the class median, the difference is 4 therms of gas per year. The cost difference is therefore 4 therms multiplied by your price per therm. The methodology page explains how the annual cost is calculated. The installed-cost range shown elsewhere on this page is a modeled range, not a quote, and it is not repeated here.