VESTA VTS-150

The 176 therms figure is computed by this site; the registry does not publish it. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the daily hot-water draw the DOE test sets for the high pattern. For this model the UEF is 0.96, taken from DOE CCD data retrieved 2026-09-19. The result holds only at the federal test's daily draw. A household that draws more or less hot water would use a different amount of gas. How much different is not available on this page. The steps behind the conversion are set out in how the annual cost is calculated.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. Among the 397 gas tankless models registered at that pattern, the VTS-150 ranks 12th lowest for energy use. That places it in the lowest quarter of its class, 6 therms below the 182 therms median. Its maximum flow rate in gallons per minute is 4.6. A home with lower daily hot-water use falls outside the test condition, so the 176 therms figure does not describe it. Energy figures for other draw patterns are not available for this model. To check other units registered in the same class, use a same-class replacement search by model number.

This text states no running cost for the VTS-150. That cost depends on your state's average residential gas price. The page applies that price to the 176 therms figure once you enter your ZIP. The cost calculator on your own ZIP shows that result at the same high draw pattern. The 6 therms gap to the class median also depends on that price, so its cost is known only after your rate is applied. The installed price range appears in its own block, with its source and date. It is a modeled installed-cost range, not a quote from an installer.