ARISTON GN40L2-3-*

The registry lists a UEF, the ratio of hot water delivered to energy used, of 0.6 for this model. This site, not the registry, computed the annual figure of 185 therms. It used the registry UEF and the DOE test's daily hot-water draw for the medium draw pattern. The source is DOE CCD, retrieved 2026-09-19. The figure applies only to that test draw. A household that uses more or less hot water than the test assumes will use a different amount of gas. The calculation is described in how the annual cost is calculated.

Among the 288 models registered as a gas tank at the medium draw pattern, this unit ranks 89th lowest for energy use. That places it in the second-lowest quarter of its class. Its 185 therms equals the class median of 185 therms, so the difference is 0 therms. The registry also lists a first hour rating, the gallons of hot water available in the first hour from a full tank, of 62 gallons. The rated volume is 38 gallons. These are test-condition capacities. A reader who wants a class-typical energy figure at the medium draw pattern is the match. A reader whose draw differs from that pattern cannot rely on this figure, and the selector by fuel, space and size covers other cases.

The running cost is not stated here. It depends on the state average residential gas price, and this page does not estimate it. Multiply 185 therms by your own gas rate, or use the cost calculator on your own ZIP. The result holds only at the medium draw pattern and the test's daily draw. The installed price range, where shown, sits in its own block with its source and date. It is a modeled installed-cost range, not a quote. To compare GN40L2-3-* with another unit in the same class, find a same-class replacement by model number. The registry gives no annual energy figure for this model, so the 185 therms value stays tied to this site's calculation.