Rheem XG30S06EC30U1

This site computed the 185 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 daily hot-water draw the DOE test sets for the medium draw pattern. For this model the UEF is 0.6. The source is the DOE CCD, retrieved 2026-09-19. The comparison class is the 288 models registered as a gas tank at the medium draw pattern. Against that class, the difference from the median is 0 therms. This model ranks 89th lowest in energy use of 288. That rank puts it in the second-lowest quarter of its class. The steps behind the annual figure are on the page explaining how the annual energy and cost are calculated.

The medium draw pattern is DOE's usage profile for a typical household of moderate size. This unit's first hour rating, the gallons of hot water available in the first hour from a full tank, is 55 gallons. Its rated volume is 29 gallons. A household whose busiest hour needs about 55 gallons matches the conditions behind the 185 therms figure. A household that draws more hot water each day than the test assumes will use more gas than 185 therms a year. How much more is not available from the registry data. If your household needs a different fuel, space or size, the water heater selector by fuel, space and size filters registered models on those terms.

The running cost is not given here because it depends on your state's average residential gas price. The page works it out from your ZIP by applying that price to the 185 therms figure at the medium draw pattern. The cost calculator for your own ZIP runs the same calculation. No installed price range is published for the XG30S06EC30U1. Its ratings fall outside the range used to fit the cost database's model, and the site does not extend that range. To check other units among the 288 models in this class, use the same-class replacement search by model number.