Rheem PROG40-36U RH67 PV*

This site calculated the 173 therms figure; the registry does not list 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 0.64. The registry data comes from the DOE Compliance Certification Database and was retrieved on 2026-09-19. The figure applies only at that test draw. A household that uses more or less hot water will use more or less gas. The class median it is compared with comes from the 288 models registered as a gas tank at the medium draw pattern. The page on how the annual energy and cost figures are calculated sets out each step of the method.

The medium draw pattern stands for a typical mid-sized household with a busy morning. This model's first hour rating, the gallons of hot water available in the first hour from a full tank, is 67 gallons. Its rated volume is 39 gallons. A plumber or seller confirming a match can check these two registry values and the UEF against the unit's label. Its rank of 44th places it in the lowest quarter of its class for energy use. That position holds only within the gas tank class at this draw pattern. It says nothing about electric, heat pump or tankless units. To compare against units in the same class, find a same-class replacement by model number.

A household whose busiest hour needs more than 67 gallons of hot water is outside what this rating covers. For such a home, the 173 therms figure does not describe its actual use. The running cost is not given in this text. It depends on your state's average residential gas price, so the page calculates it from your ZIP. That result applies at the federal test's daily draw, and your household's own hot-water use will change it. The running-cost calculator for your own ZIP shows the figure for your state's rate. The installed price range appears in its own block on this page, with its source and date. It is a modeled range, not a quote.