LAARS LT150NXX1

The registry lists a UEF, the ratio of hot water delivered to energy used, of 0.98 for this model. This site combines that UEF with the DOE test's daily hot-water draw for the high draw pattern. The result is 173 therms of natural gas a year, which the registry does not publish itself. It sits 9 therms below the class median of 182 therms. The 397 models in the class are all registered as a gas tankless unit at the high draw pattern. This model ranks 1st lowest for energy use of 397, in the lowest quarter of its class. The source is DOE CCD, retrieved 2026-09-19. The method behind the annual figure is explained in how the annual cost is calculated.

The maximum flow rate in gallons per minute is 4.3 for this model. The registry data used here does not state the temperature rise behind that flow rate, so that value is not available. The energy figure applies to the high draw pattern, meaning a larger household, or one where showers and laundry overlap. For that kind of use, the 173 therms figure is the value to compare against the class median of 182 therms. The figure does not describe a household with a lower or different draw pattern. The yearly gas use for that case is not available here. The selector by fuel, space and size lists other options by those inputs.

The running cost is not written in the text, because it depends on the state average residential gas price. That price is applied to the 173 therms figure, and it differs by state. The cost calculator on your own ZIP applies your state's price to this figure. The gap of 9 therms from the class median is measured in energy, and its cost depends on the same price. The modeled installed-cost range appears in its own block, with its source and date. It is a modeled range, not a quote. To look for a same-class model, use find a same-class replacement by model number with LT150NXX1.