ARISTON GN30T2-3-*

The figure of 185 therms is a computed value, not a registry entry. This site calculated it from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.6 for this model. It also used the daily hot-water draw that the federal test sets for the medium draw pattern. The source is DOE CCD, retrieved 2026-09-19. Among 288 gas tank models at this draw pattern, this unit has the 89th lowest energy use. That places it in the second-lowest quarter of its class. The class median is 185 therms, so the difference is 0 therms. The method behind the annual cost is documented separately.

The figure fits a household that matches the medium draw pattern, meaning a typical household on a busy morning. It does not describe a home that uses much more or much less hot water. Actual gas use in such a home will differ from 185 therms. The registry also lists a first hour rating, the gallons of hot water available in the first hour from a full tank, of 67 gallons. The rated volume is 29 gallons. Neither number shows whether this size meets a particular household's peak demand. To narrow the options by fuel, space and size, use the water heater selector. A same-class unit can be found by model number through the replacement finder.

Running cost depends on your own rate. It is the 185 therms of natural gas multiplied by your state's average residential gas price, and that price is not stated in this text. The cost calculator applies your ZIP to this model's 185 therms, so the result uses your state's price rather than an estimate. Because the figure belongs to the medium draw pattern, the result holds only for that use. An installed price range is not published for this model. Its ratings lie outside the range the cost database's model was fitted on, and the range is not stretched past it. The class median of 185 therms is a comparison point only, not a cost.