STATE GCF-40 1**

The 173 therms figure is computed by this site, not taken from the registry. It combines the model's UEF, the ratio of hot water delivered to energy used, with the daily hot-water draw that the DOE test assigns to the medium pattern. For this model the UEF is 0.64, from DOE CCD data retrieved 2026-09-19. The figure applies only at that test draw. A household that uses more or less hot water will use a different amount of gas. Among the 288 gas tank models at medium draw, this one ranks 44th lowest in energy use. That rank compares registered test results only. It does not describe how any unit performs after installation, and this data does not cover that.

DOE assigns the medium draw pattern to a typical household of moderate size with a busy morning peak. This model's first hour rating, the gallons of hot water available in the first hour from a full tank, is 70 gallons. Its rated volume is 38 gallons. A household whose busiest hour needs more than 70 gallons falls outside what that rating covers. Its yearly gas use would also differ from 173 therms, because the test draw no longer matches its use. Models tested at other draw patterns are not part of this comparison of 288 models. To compare units across fuel, space and size, use the water heater selector by fuel, space and size. To find units in the same class, try the same-class replacement search by model number.

This text does not state a running cost for the STATE GCF-40 1**. That cost depends on your state's average residential gas price, so the page computes it from your ZIP. The running cost calculator for your own ZIP applies that price to 173 therms a year. The gap of 12 therms below the 185 therms class median turns into a cost difference only at your own gas rate. The method behind the annual cost figure explains each input. The installed price range appears in its own block with its source and date. It is a modeled range for installed cost, not a quote. Any figure for your own site is not available from this data.