VESTA VTS-199

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 DOE test's daily hot-water draw for the high draw pattern. This model's UEF is 0.96. The source is DOE's Compliance Certification Database (CCD), retrieved 2026-09-19. The comparison class is the 397 models registered as a gas tankless unit at the high draw pattern. Their median is 182 therms a year, and this model sits 6 therms below it. The figure describes the test household's usage, not a measured bill from any real home. The steps behind it are set out in how the annual energy and cost are calculated.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. A home that fits that description matches the condition behind the 176 therms figure. The unit's maximum flow rate in gallons per minute is 5.9, the most hot water it is rated to deliver at once. A home that needs more than 5.9 gallons per minute at the same moment asks for more than this rating. A smaller household with lighter daily use does not match the test condition. Its yearly gas use with this model is not available from this data. If this model does not fit the household, a same-class replacement search by model number lists other gas tankless units at the high draw pattern.

This page does not state a running cost in the text. The cost of 176 therms of natural gas a year depends on your state's average residential gas price. For that reason, the page computes it from your ZIP. At the same gas price, the 6 therms gap below the class median of 182 therms lowers the cost too. How much it saves in money depends on that same rate, so no figure is estimated here. To see the result for your own address, use the running-cost calculator for your ZIP. The installed price range appears in its own block on this page, with its source and date. It is a modeled installed-cost range, not a quote from an installer.