A. O. SMITH GPCX-50L 1**

The A. O. SMITH GPCX-50L 1** is listed with a UEF of 0.9. UEF, the ratio of hot water delivered to energy used, comes from the registry. The registry does not state an annual figure. This site computes 188 therms from that UEF and the DOE test's daily hot-water draw for the high draw pattern, using DOE CCD data retrieved 2026-09-19. Among the 414 models registered as a gas tank at this draw pattern, the unit ranks 1st lowest for energy use. That places it in the lowest quarter of its class, 72 therms below the median of 260 therms.

The high draw pattern describes a larger household, or one where showers and laundry overlap. The 188 therms figure applies only under that condition. The listing gives a first hour rating, the gallons of hot water available in the first hour from a full tank, of 118 gallons, and a rated volume of 49 gallons. A household whose use differs from this pattern would see a different annual figure, and this page has no value for other patterns. To compare by fuel, space and size, the water heater selector covers those filters. To find a unit in the same class, look up a replacement by model number.

Running cost is not shown in the text because it depends on the state average residential gas price, which differs from reader to reader. The 188 therms figure is a quantity of gas, and the yearly cost follows once your own rate is applied to it. The cost calculator does this from your ZIP, and the calculation method explains how the annual cost is worked out. The gap of 72 therms from the class median of 260 therms is a difference in gas use, not in cost, until a rate is applied. An installed price range is not published for this model. Its ratings lie outside the range the cost database's model was fitted on, and that range is not stretched past it.