LOCHINVAR TK-110U-E 2**

This model's 137 therms is computed by this site, not published by the registry. It starts from the registry's 0.81 UEF, the ratio of hot water delivered to energy used. It then applies the DOE test's daily hot-water draw for the medium draw pattern. The figure is for natural gas and comes from the DOE CCD, retrieved 2026-09-19. The unit's maximum flow rate in gallons per minute is 3.5. That is a capacity rating, and it does not enter the annual energy calculation shown here. The method behind the annual cost is described on the methodology page.

The class is the 80 models registered as a gas tankless unit at the medium draw pattern. This unit sits in the second-highest quarter of that class for energy use. Its 137 therms is 2 therms above the class median of 135 therms. It ranks 52nd lowest in energy use of 80. It suits a household that matches the medium draw pattern and wants a figure to check against the registry listing. It suits less well a household whose hot-water use differs from that pattern. The figure applies only at the federal test's daily draw, so actual use in a home can differ. For another unit in the same class, use the replacement finder by model number.

The running cost is not stated in the text, because it depends on the state average residential gas price for your ZIP. Multiplying 137 therms by your own gas rate per therm gives a yearly figure for this unit. The cost calculator on your own ZIP does this for you. The same rate converts the 2 therms gap from the 135 therms class median into cost. The installed price appears in its own block, as a modeled range and not a quote, with its source and date. If fuel, space or size is still open, the selector by fuel, space and size covers those. The running cost for this model is unknown until a rate is entered.