LOCHINVAR GDV-50 3**

The 256 therms figure does not come from the registry itself. This site calculated it from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.66 for this model. The second input is the DOE test's daily hot-water draw for the high draw pattern. The UEF was taken from DOE's CCD registry, retrieved 2026-09-19. So the figure applies only at that test draw. A home that uses more hot water than the test assumes will burn more gas than 256 therms, and a home that uses less will burn less. This data does not show how far a particular household would be above or below that figure.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. For that kind of use, the capacity figure to check is the first hour rating, the gallons of hot water available in the first hour from a full tank. This model lists 77 gallons from a rated volume of 48 gallons. For energy use, it ranks 192nd lowest of the 414 gas tank models at the high draw pattern. That puts it below the class median, not near the lowest end of the class. A smaller household that uses less hot water falls outside the conditions behind the figure. This data gives no energy figure for other draw patterns. To compare other fuels or sizes, use the water heater selector by fuel, space and size.

The running cost is not given here because it depends on your state's average residential gas price. The page works it out from your ZIP by applying that rate to the 256 therms test-draw figure. You can repeat that step in the cost calculator for your own ZIP. The page on how the annual cost is calculated lists each input. The installed price range in its own block is a modeled range with its source and date, not a quote. If you are matching a unit that is already installed, the same-class replacement search by model number lists other gas tank models at the high draw pattern to compare with the GDV-50 3**.