Ranein RO8K-Y

The figure of 135 therms is not a registry entry. This site computed it from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.82 for this model. It also uses the daily hot-water draw the DOE test assigns to the medium draw pattern, which describes a typical three- or four-person household. The source is the DOE CCD, retrieved 2026-09-19. A household that uses more or less hot water than the test assumes will land on a different annual figure, and this page has no value for other usage. The method behind the annual calculation is documented separately.

The comparison group is the 80 models registered as a gas tankless unit at the medium draw pattern. This model ranks 32nd lowest in energy use of 80, which places it in the second-lowest quarter of its class. Its 135 therms equals the class median of 135 therms, so the difference is 0 therms. The rank describes this one test condition only. The maximum flow rate in gallons per minute is 3.2. This page has no data on how many fixtures that flow supports at once, so it draws no conclusion about simultaneous use.

The figure suits a reader who wants to confirm that a unit with a UEF of 0.82 matches the 135 therms shown at the medium draw pattern. It does not suit a household whose hot-water use differs clearly from that pattern, because no figure for another pattern is available here. The running cost is not written in the text, since it depends on your state's average residential gas price. Apply your own rate to 135 therms, or use the cost calculator for your own ZIP. To compare units of the same class, you can find a same-class replacement by model number. The modeled installed-cost range has its own block with its source and date.