Lennox WHGS050T40NANE****

It holds 47 gallons in the test, 3 gallons less than its 50-gallon sold size. Over one hour from a full tank, it gave 86 gallons in the test (its first-hour rating). Its tank holds 47 gallons, so reheating adds 39 gallons during the first hour. 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.

As of Oct 26, 2026, it was not listed as ENERGY STAR certified. In the test, 34% of its energy does not reach the hot water (UEF 0.66). Its test simulated a day of high hot water use (its draw pattern). Of 434 gas storage models with the same draw pattern, 213 have a higher UEF and 209 a lower one. Its UEF is the median for its type and draw pattern. When it reheats water in the test, 80% of the energy it uses ends up in the water.

Its test figures match those of 2 other basic models. The AMERICAN STANDARD WATER HEATERS and Ariston brands list one or more of them. You can find the whole group on the page for the AMERICAN STANDARD WATER HEATERS GN50T2-3-*.