ARISTON GSN50L2-3-*

The figure of 260 therms is computed by this site, not published by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, of 0.65 with the daily hot-water draw that DOE's test uses for the high draw pattern. The source is the DOE CCD, retrieved 2026-09-19. The figure applies only to natural gas and only at that draw, so a household that uses more or less hot water than the test assumes will use a different amount. The comparison group is the 414 models registered as a gas tank at the high draw pattern. How the annual cost is calculated describes the method in full.

Within that group, this model ranks 204th lowest energy use of 414, which places it in the second-lowest quarter of its class. Its use of 260 therms equals the class median of 260 therms, a difference of 0 therms. The high draw pattern describes a larger household, or one where showers and laundry overlap, so the figure is most relevant to that situation. The first hour rating, the gallons of hot water available in the first hour from a full tank, is 78 gallons, and the rated volume is 48 gallons. These data do not show whether that covers your own busiest hour. The selector by fuel, space and size can help compare other options.

The figure of 260 therms does not describe a household with lighter hot-water use than the high draw pattern, because the test draw is a fixed value and not a measurement of any home. It also says nothing about cost. The running cost is not stated here because it depends on your state's average residential gas price, and that price is not part of this model's data. Enter your ZIP in the cost calculator on your own ZIP to compute it from the 260 therms figure. To look at units in the same class as this ARISTON GSN50L2-3-*, you can find a same-class replacement by model number. The modeled installed-cost range appears in its own block, with its source and date.