Ruud PROG39S-38U RH62 EC1*

The 188 therms figure comes from this site's calculation. The registry does not publish it. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the DOE test's daily hot-water draw for the medium pattern. This model's UEF is 0.59. The source is the DOE CCD, retrieved 2026-09-19. The figure holds only at the test's daily draw. A household drawing more or less hot water will use a different amount of gas, and that amount is not available here. The page on how the annual cost is calculated explains how UEF and the test draw are combined.

The comparison group is the 288 models registered as a gas tank at the medium draw pattern. This model ranks 186th for lowest energy use out of 288. That places it in the second-highest quarter of its class for energy use, 3 therms above the class median. The tank holds 37 gallons. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 68 gallons. These ratings are what DOE used when it placed the model in the medium pattern. A household whose daily use matches that pattern is the case the 188 therms figure describes.

This text does not give a running cost. It depends on your state's average residential gas price, so the page calculates it from your ZIP and the 188 therms figure. The cost calculator for your ZIP shows that result. The cost figure does not fit a household that draws well beyond the medium pattern, and no figure for heavier use is available. The installed price range is also not published. This model's ratings lie outside the range the cost database's model was fitted on, and the range is not stretched beyond that. To check other gas tank models in the same class, find a same-class replacement by model number.