Ranein RH8K-NG

The figure of 135 therms is computed by this site, not by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, of 0.82 with the daily hot-water draw the DOE test assigns to the medium draw pattern. The source is DOE CCD, retrieved 2026-09-19. The fuel is natural gas, and the figure holds only at that draw. A household that uses more or less hot water than the test assumes will use a different amount of gas. The registry does not contain a measured value for any individual home.

Among the 80 models registered as a gas tankless unit at the medium draw pattern, this unit ranks 32nd lowest in energy use, which places it in the lower half of its class. Its 135 therms matches the class median of 135 therms, so the difference is 0 therms. Rank and median apply only to that class and draw pattern. The registry lists a maximum flow rate in gallons per minute of 3.6. That rating is not an input to the annual figure computed here. The unit suits a reader whose hot-water use resembles the medium draw pattern. It does not suit a comparison made at a different draw pattern. To check a same-class alternative, find a same-class replacement by model number.

Running cost is not stated in this text because it depends on your state average residential gas price. To check it, multiply 135 therms by the price per therm you pay. Alternatively, use the cost calculator on your own ZIP, which applies your state's price to the same figure, and read how the annual cost is calculated. The energy figure reflects data retrieved 2026-09-19. The installed price appears in its own block with its source and date, as a modeled range and not a quote, so it is not repeated here. If you are comparing other fuels, the selector by fuel, space and size covers them.