Rheem SCG40T03ST34U1

This site computed the 188 therms figure. The registry does not list it. The figure 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. For this model the UEF is 0.59. The source is the DOE CCD, retrieved 2026-09-19. The medium pattern stands for a typical household that uses a moderate amount of hot water on a busy morning. If your household uses more or less hot water than the test assumes, your yearly use will not match 188 therms. This data does not show how large that difference would be. The figure covers natural gas only, because that is the fuel this model is registered for.

The comparison class is the 288 models registered as a gas tank at the medium draw pattern. At the test draw, their median is 185 therms a year, and this model sits 3 therms above it. Among those 288 models, it ranks 186th for lowest energy use. The listing gives a rated volume of 38 gallons. It also gives a first hour rating, the gallons of hot water available in the first hour from a full tank. For this model that rating is 67 gallons. A home whose busiest hour stays within 67 gallons fits the conditions behind this rating. A home that needs more in its busiest hour falls outside those conditions. To check other models in the same class, use the same-class replacement finder by model number.

This text does not state the running cost, because it depends on your state's average residential gas price. The page works it out from 188 therms and the rate for the ZIP you enter. You can repeat that step in the water heater cost calculator for your ZIP. The method is explained in how the annual running cost is calculated. A cost worked out this way carries the same condition as the energy figure: the medium draw pattern at the test's daily draw. The installed price range appears in its own block on this page, with its source and date. It is a modeled installed-cost range, not a quote from an installer.