LOCHINVAR GCF-50 1**

The 245 therms figure is not in the registry itself. This site calculated it from the registry's UEF, the ratio of hot water delivered to energy used. The second input is the DOE test's daily hot-water draw for the high draw pattern. This model's UEF is 0.69. It comes from the DOE Compliance Certification Database, retrieved 2026-09-19. The class has 414 gas tank models registered at the high draw pattern. In that class, this model has the 130th lowest energy use. That puts it in the second-lowest quarter of its class for energy use. Each step is set out in how this site calculates annual energy and cost.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. This model's first hour rating, the gallons of hot water available in the first hour from a full tank, is 84 gallons. Its rated volume is 48 gallons. The 245 therms figure fits homes whose use matches that pattern. A smaller household with lighter daily use does not match the test condition. For that case, an energy figure at a lower draw pattern is not available in this data. The comparison covers only gas tank models at the high draw pattern, so other heater types are not ranked here. To compare by fuel, space and size, use the water heater selector. To match an existing unit within this class, find a same-class replacement by model number.

The 15 therms gap below the 260 therms class median is a difference in energy, not in cost. Its yearly value depends on the average residential gas price in the reader's state. For that reason, this text gives no running cost. The page works it out from the ZIP entered in the running cost calculator for your ZIP. The installed-cost range appears in its own block, with its source and date. It is a modeled range, not a quote. One input remains unknown: your household's actual daily hot-water use. If that use differs from the federal test's draw, the real energy use will differ from 245 therms. The running cost will differ with it.