Rheem PRO+G40S-40N RH67 PD

The 171 therms figure is calculated by this site, not published by the registry. It combines two inputs. The first is the registry's UEF, the ratio of hot water delivered to energy used, which is 0.65 for this model. The second is the daily hot-water draw that the federal test sets for the medium draw pattern. The underlying record comes from the DOE Compliance Certification Database, retrieved 2026-09-19. The figure holds only at that test draw. A household that uses more hot water each day will burn more gas than 171 therms, and one that uses less will burn less. The page on how the annual cost is calculated sets out each step of the calculation.

Among the 288 gas tank models registered at the medium draw pattern, this one ranks 33rd lowest in energy use. At the test draw, that places it 14 therms under the class median. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 69 gallons. Its rated volume is 39 gallons. DOE uses the medium draw pattern to represent a typical household's daily hot-water use. The comparison fits households whose daily use is close to that pattern. For heavier or lighter daily use, the registry lists no energy figure for this model, so its rank at other draw patterns is not available. To check another model in the same class, use the same-class replacement search by model number.

This page does not give a running cost in the text. The cost of 171 therms of natural gas depends on your state's average residential gas price. The page works it out from your ZIP instead. Enter it in the cost calculator for your own ZIP to see this model's figure at the medium draw pattern. The 14 therms gap to the class median also has no fixed cost value. That value depends on the same local rate. The installed price range appears in its own block on this page. It is a modeled installed-cost range with its own source and date. It is not a quote, and it is separate from the running cost.