Ariston GSN50T1-3-*

It holds 47 gallons in the test, 3 gallons less than its 50-gallon sold size. It delivers 86 gallons of hot water in the test's first hour. Reheating lets it give 39 gallons beyond the 47 gallons in its tank. In the first hour, 162 of the 763 gas storage models give more hot water. 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 tests, 65% of the energy it uses ends up as hot water (UEF 0.65). The daily hot water use in the test, called its draw pattern, was high. Of 434 gas storage models with the same draw pattern, 225 have a higher UEF. For its type and draw pattern, the UEF runs from 0.61 to 0.90. The water took in 82% of the energy used to reheat it (its recovery efficiency).

Its test figures match those of 3 other basic models. The AMERICAN STANDARD WATER HEATERS and Lennox brands list one or more of them. You can find the whole group on the page for the AMERICAN STANDARD WATER HEATERS GSN50T1-3-*.