GSW WATER HEATERS GPVL-50 2**

The figure of 235 therms is computed by this site, not published by the registry. It starts from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.72 for this model. That is combined with the DOE test's daily hot-water draw for the high draw pattern. This pattern describes a larger household, or one where showers and laundry overlap. The registry data was retrieved on 2026-09-19, and the source is the DOE CCD. Among the 414 gas tank models at this draw pattern, this unit has the 50th lowest energy use, which puts it in the lowest quarter of its class. Details of how the annual cost is calculated are on the methodology page.

The first hour rating, the gallons of hot water available in the first hour from a full tank, is 79 gallons. The rated volume is 49 gallons. The energy figure suits a household whose hot-water use resembles the high draw pattern, because 235 therms is the amount for that test draw. The 25 therms gap below the class median of 260 therms applies only to that same draw. It does not describe a household whose real use differs from the test draw, and this page does not estimate that use. Whether 79 gallons covers a given household's busiest hour is not in the registry data, so it is not stated here. A selector by fuel, space and size can help compare other models in those cases.

The running cost is not stated in the text because it depends on the state average residential gas price. Multiplying 235 therms by that price gives the yearly cost at the high draw pattern. The 25 therms gap from the class median of 260 therms converts to a cost the same way. The cost calculator on your own ZIP applies the gas price for your state. 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, and its figures are not repeated in this text.