LOCHINVAR GCFL-40 1**

The figure of 168 therms was computed by this site, not by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, of 0.66 with the daily hot-water draw in the DOE test for the medium draw pattern. The figure holds only at that draw. A household that uses more or less hot water will see a different total. The class median is 185 therms, so this model sits 17 therms below it. Its rank of 27th lowest of 288 places it in the lowest quarter of its class. The comparison covers only models registered as a gas tank at the medium draw pattern. The source is DOE CCD, retrieved 2026-09-19.

This model fits a household whose hot-water use matches the medium draw pattern. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 65 gallons. The rated volume is 38 gallons. Compare the first hour rating with your household's busiest hour, since the annual figure does not show that. To compare other fuels, spaces and sizes, use the water heater selector. If you need a unit of the same class, you can find a same-class replacement by model number.

This model fits less well where daily use is far from the medium draw pattern, because the 168 therms figure would not apply. The registry data gives no annual energy for other draw patterns, so that value is not available here. The running cost is not stated on this page. It depends on your state average residential gas price, which is applied to the 168 therms figure. Enter your ZIP in the cost calculator to use your own rate. The annual cost method sets out the steps. A modeled installed-cost range appears in its own block, with its source and date.