Ruud PRO+G50S-40N RH67 PD

The 245 therms figure is computed by this site, not taken from the registry. 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 high pattern. This unit's UEF is 0.69. The UEF comes from the DOE Compliance Certification Database (CCD), retrieved 2026-09-19. The figure holds only at that test draw, so a household drawing more or less hot water will use a different amount. Each step is set out in how the annual cost is calculated. Against its class, the unit ranks 130th lowest energy use of 414. That places it in the second-lowest quarter of its class for energy use.

The high draw pattern describes a larger household, or one where showers and laundry overlap. This unit is registered for that use. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 78 gallons, from a rated volume of 48 gallons. A home whose peak hour needs more than 78 gallons falls outside what the rating covers. A smaller household that draws less than the DOE test assumes also sits outside the condition behind 245 therms. Its actual use is not available here. To compare other gas tanks by size, use the selector by fuel, space and size. For a like-for-like swap, you can find a same-class replacement by model number.

The running cost is not stated in this text, because it depends on your state's average residential gas price. The page computes it from your ZIP, using the 245 therms figure at the high draw pattern. The 15 therms gap below the 260 therms class median becomes a cost difference only once that same rate is applied. The size of that difference is therefore not known until your rate is entered. The modeled installed-cost range sits in its own block, with its source and date. It is a modeled range, not a quote. To rerun the running cost on another rate, use the cost calculator on your own ZIP.