A. O. Smith GCGH-50 2**

It holds 48 gallons in the test, 2 gallons less than its 50-gallon sold size. Starting full, it gives 76 gallons of hot water in its first hour of use. Reheating lets it give 28 gallons beyond the 48 gallons in its tank. In the first hour, 429 of the 763 gas storage models give more hot water. The median gas storage model gives 78 gallons in the first hour of the test.

On Oct 26, 2026, this heater was not listed as ENERGY STAR certified. In tests, 63% of the energy it uses ends up as hot water (UEF 0.63). Its test ran at the high level of daily hot water use. Its UEF is lower than that of 339 of the 434 gas storage models with its draw pattern. A UEF of 0.66 is the median for its type and draw pattern. The water took in 77% of the energy used to reheat it (its recovery efficiency).

It is the basic model for GCGH-50 2** and GCGH-50 2*1. All of its test figures are shared by 7 other basic models. Besides this brand, 4 brands list one or more of them. For the full group, see the A. O. Smith G6N-UT5040NVR 5** page.