ARISTON PV50SLN*

The 245 therms figure comes from this site's calculation, not from the registry itself. It combines the registry's UEF, the ratio of hot water delivered to energy used, of 0.69 with the DOE test's daily hot-water draw for the high pattern. The figure holds only at that test draw and was not measured in any home. The registry data come from the DOE CCD, retrieved on 2026-09-19. Among the 414 gas tank models registered at the high draw pattern, this one ranks 130th lowest in energy use. That puts it in the second-lowest quarter of its class, not at the top of it. The page on how the annual figure is calculated lists each input and step.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. For that use, the registry lists a first hour rating, the gallons of hot water available in the first hour from a full tank, of 80 gallons. The rated volume is 48 gallons. If a household draws much less hot water than the high pattern assumes, the 245 therms figure does not describe its use. A registry figure for this model at a lower draw pattern is not available in this data. A plumber replacing this unit can find a same-class replacement by model number. That search compares models within the same gas tank, high draw pattern class used for the 130th ranking.

The running cost is not stated in this text because it depends on the reader's state average residential gas price. The page works it out from the 245 therms yearly figure and the rate for the reader's ZIP code. Enter a ZIP in the water heater cost calculator for your own ZIP to see that result. No cost is estimated here. It also holds only at the high draw pattern's test usage. The installed price range appears in its own block, with its source and date. It is a modeled installed-cost range, not a quote from an installer. Neither the running cost nor the installed range changes the energy rank of 130th among 414 models.