FRIEDRICH PROG40-36P RH67 PV

The 163 therms figure is computed by this site, not published by the registry. It combines UEF, the ratio of hot water delivered to energy used, of 0.68 with the daily hot-water draw that the DOE test assigns to the medium draw pattern. That pattern represents a typical household on a busy morning. The figure therefore describes federal test conditions for natural gas, not the metered use of any single home. A home that draws more or less hot water than the test will use more or less gas than 163 therms. The source is DOE CCD, retrieved 2026-09-19, and changes made after that date are not reflected here.

Against its class, this model uses 22 therms less than the median of 185 therms. It ranks 5th lowest energy use of 288 models registered as a gas tank at the medium draw pattern, which places it in the lowest quarter of its class for energy use. This comparison covers energy use only. It suits a natural gas household whose hot-water use resembles the medium pattern. It does not settle capacity: the rated volume is 38 gallons, and the first hour rating, the gallons of hot water available in the first hour from a full tank, is 71 gallons. A household whose busiest hour needs more than that should check size with the selector by fuel, space and size.

Running cost is not stated here because it depends on your state's average residential gas price. Multiply 163 therms by your own rate, or enter your ZIP in the cost calculator, which applies the state average to this figure. The steps behind that calculation are described in how the annual cost is calculated. Any result keeps the conditions of the energy figure: the medium draw pattern and the federal test's daily draw. The class median of 185 therms gives a reference point if you want to see what the 22 therms difference amounts to at your rate. The modeled installed-cost range appears in its own block on this page, with its source and date, and is not a quote.