Rheem PRO+G55-45U RH59 EC1*

The 273 therms figure is calculated by this site. It does not come from the registry. The registry lists a UEF, the ratio of hot water delivered to energy used, of 0.62 for this model. This site combines that UEF with the DOE test's daily hot-water draw for the high pattern. The UEF comes from the DOE CCD, retrieved 2026-09-19. Among the 414 gas tank models at the high draw pattern, this unit ranks 367th lowest in energy use. That puts it in the highest quarter of its class for energy use. The steps behind the annual figure are set out in how the annual cost is calculated.

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 99 gallons. Its rated volume is 55 gallons. A household that uses about as much hot water a day as the federal test can compare its use with the 273 therms figure directly. A household that uses more or less will burn a different amount of gas. This page does not have that figure. To compare units in the same class, you can find a same-class replacement by model number or use the water heater selector by fuel, space and size.

This text does not state a running cost. The cost of 273 therms a year depends on your state's average residential gas price. The page calculates it from your ZIP in the running cost calculator for your ZIP. This model uses 13 therms more gas than the class median of 260 therms, so it costs more at the same rate. The size of that difference is not available without your gas price. The installed price range appears in its own block with its source and date. It is a modeled installed-cost range, not a quote. The energy and cost figures both assume the high draw pattern. This data does not cover use outside that pattern.