eyoo EO8K-W

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 federal test's daily hot-water draw for the medium draw pattern. The energy source is natural gas, and the underlying registry data comes from the DOE CCD, retrieved 2026-09-19. Because it is a calculation under test conditions, it does not measure gas use in any particular home. Incoming water temperature and how a household actually draws hot water are not in the data, so their effect on this unit is unknown. The method is set out in how the annual cost is calculated.

Against the 80 models registered as a gas tankless unit at the medium draw pattern, this unit sits at the class median of 135 therms, a difference of 0 therms. It ranks 32nd lowest in energy use, so on this figure alone it neither uses less nor more gas than the typical model in its class. It suits a household whose hot-water use resembles the medium draw pattern. It fits less well where use is far heavier or lighter, because figures for other draw patterns are not shown here. The registry lists a maximum flow rate in gallons per minute of 3.2. The temperature rise that flow applies to is not available on this page. A water heater selector by fuel, space and size can narrow the comparison.

The running cost is not written as an amount here, because it depends on the average residential gas price in the reader's state. To check it, multiply 135 therms by that price per therm, or use the cost calculator for your own ZIP, which applies the price for the ZIP entered. Actual use will differ from 135 therms when the household's draw differs from the medium draw pattern. The installed price range is a modeled installed-cost range, not a quote. It appears in its own block with its source and date and is not repeated in this text. If you are checking a swap, you can find a same-class replacement by model number starting from EO8K-W.