STATE TK-110U-I 2**

The registry lists a UEF, the ratio of hot water delivered to energy used, of 0.81 for this unit. This site computed 137 therms from that UEF and the daily hot-water draw for the medium draw pattern. The registry does not publish that annual figure itself. The source is the DOE CCD, retrieved 2026-09-19. The figure holds only for natural gas at the test draw. A household that uses more or less hot water than the test will see a different result. This page has no annual figure for any other draw pattern.

Its rank is 52nd lowest energy use of 80 models, which puts it in the second-highest quarter of its class for energy use. Its 137 therms is 2 therms above the class median of 135 therms. The listed maximum flow rate in gallons per minute is 3.5. That rating limits how many fixtures can run at once and is not part of the annual energy figure. The unit suits a reader whose household matches the medium draw pattern and who wants to confirm a registry figure. It does not suit a reader whose hot-water use is far from that pattern. This page does not show how widely the class varies, so it makes no wider comparison.

The running cost is not written here because it depends on your state average residential gas price. To estimate it, multiply 137 therms by your local price per therm. The cost calculator does this from your own ZIP. The gap of 2 therms from the class median changes the yearly cost by that many therms times your rate. How the annual cost is calculated is set out on the methodology page. To compare units in the same class, you can find a same-class replacement by model number. The modeled installed-cost range appears in its own block with its source and date. It is a range, not a quote.