Ariston GSN50T2-3-*

It holds 47 gallons in the test, 3 gallons less than its 50-gallon sold size. It delivers 82 gallons of hot water in the test's first hour. That is 35 gallons more than its tank holds, since it reheats during the hour. Among 763 gas storage models, 280 have a higher first-hour rating. The median gas storage model gives 78 gallons in its first hour.

On Oct 26, 2026, this heater was not listed as ENERGY STAR certified. In the test, 37% of its energy does not reach the hot water (UEF 0.63). In the test, daily hot water use was set to high (its draw pattern). Of 434 gas storage models with the same draw pattern, 339 have a higher UEF. On its draw pattern, the median gas storage UEF is 0.66. When it reheats water in the test, 82% of the energy it uses ends up in the water.

All of its test figures are shared by one other basic model. The brand name on that one is AMERICAN STANDARD WATER HEATERS. For the full group, see the AMERICAN STANDARD WATER HEATERS GSN50T2-3-* page.