LOCHINVAR FMDV-50 2**

The annual figure for this model is 194 therms of natural gas at the medium draw pattern. This site computed it, and the registry did not. The calculation uses the registry's UEF, the ratio of hot water delivered to energy used, and the daily hot-water draw of the DOE test. The registry lists a UEF of 0.57 for this unit. The class median is 185 therms, so this model sits 9 therms above it. It ranks 278th lowest in energy use among the 288 models registered as a gas tank at this draw pattern. The source is DOE CCD, retrieved 2026-09-19. A household with a different daily draw would use a different amount, and this page does not estimate it.

This model suits a household whose daily use is close to the medium draw pattern, because that is the condition of the 194 therms figure. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 67 gallons. The rated volume is 47 gallons. Whether those ratings cover a given household is a question for the water heater selector, which filters by fuel, space and size. A reader who ranks purely by energy use will find this model at 278th of 288, in the highest quarter of its class. A plumber replacing it can look up a same-class unit by model number with the replacement finder. This page does not compare other models.

The running cost depends on the state average residential gas price, so this text states no cost. The cost calculator applies the reader's own ZIP to the 194 therms figure. The methodology page explains how the annual cost is calculated. At any given gas price, the 9 therms difference from the class median of 185 therms is priced at that same rate. An installed price range is not published for this model. Its ratings lie outside the range the cost database's model was fitted on. That range is not stretched past its limit, and no installed price is estimated here.