Friedrich PROG50S-40U RH60 EC1*

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 85 gallons in the test (its first-hour rating). That is 37 gallons more than its tank holds, since it reheats during the hour. Of 763 gas storage models, 192 give more hot water in the first hour. Among gas storage models, the median first-hour rating is 78 gallons.

It was not listed as ENERGY STAR certified on Oct 26, 2026. In tests, 63% of the energy went to hot water, so its UEF is 0.63. Its test simulated a day of high hot water use (its draw pattern). 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. Of the energy spent to reheat water, 83% goes into it (its recovery efficiency).

Its test figures match those of 4 other basic models. The Rheem, Richmond, and Ruud brands list one or more of them. You can find the whole group on the page for the Rheem PROG50S-40U RH60 EC1*.