Kepler MGWH199IXNP

The registry lists this model's UEF, the ratio of hot water delivered to energy used, as 0.95. This site combines that value with the DOE test's daily hot-water draw for the high draw pattern to reach 178 therms of natural gas a year. The registry does not publish that annual figure itself. The underlying data comes from DOE CCD, retrieved 2026-09-19. Among the 397 models registered as a gas tankless unit at the high draw pattern, this one has the 45th lowest energy use. That places it in the lowest quarter of its class. The class median is 182 therms, so this unit sits 4 therms below it. The method for the annual figure is described on the methodology page.

The figure fits a larger household, or one where showers and laundry overlap, because it is tied to the high draw pattern. The maximum flow rate in gallons per minute is listed as 5.7. That is a rated ceiling, and it does not show how many fixtures can run at once in a given home. A household with lighter use falls under a different draw pattern, and this page carries no figure for that pattern, so it is not available here. The gap of 4 therms to the class median of 182 therms also comes from the test draw, not from metered use in any home. To compare other fuels, spaces or sizes, use the water heater selector, or find a same-class replacement by model number.

The running cost is not written in the text because it depends on the state average residential gas price, which differs by reader. The cost calculator applies the price for your ZIP to 178 therms, the figure for the high draw pattern at the federal test's daily draw. Any result therefore carries the same condition as the energy figure. A household that uses more or less hot water than the test draw will have a different real cost, and that difference is unknown here. The modeled installed-cost range appears in its own block on the page, with its source and date, as a range and not a quote. This text does not restate it.