Ariston GN50L2-3-*

It holds 48 gallons in the test, 2 gallons less than its 50-gallon sold size. Over one hour from a full tank, it gave 78 gallons in the test (its first-hour rating). That is 30 gallons more than its tank holds, since it reheats during the hour. Among 763 gas storage models, 366 have a higher first-hour rating. Its first-hour rating matches the median for gas storage models.

It was not listed as ENERGY STAR certified on Oct 26, 2026. In tests, 65% of the energy it uses ends up as hot water (UEF 0.65). Its test ran at the high level of daily hot water use. Of 434 gas storage models with the same draw pattern, 225 have a higher UEF and 179 a lower one. A UEF of 0.66 is the median for its type and draw pattern. When it reheats water in the test, 78% of the energy it uses ends up in the water.

All of its test figures are shared by 2 other basic models. Of those, one or more are under the AMERICAN STANDARD WATER HEATERS and Lennox brands. You can find the whole group on the page for the AMERICAN STANDARD WATER HEATERS GN50L2-3-*.