VESTA VRS-150

The 178 therms figure is calculated by this site, not published by the registry. It starts from the registered UEF, the ratio of hot water delivered to energy used. For this model that ratio is 0.95. The site applies it to the DOE test's daily hot-water draw for the high pattern. The UEF comes from the DOE CCD, retrieved 2026-09-19. The annual figure holds only at that test draw. A home drawing more or less hot water will use more or less gas, and by how much is not available here. The 4 therms gap to the class median is measured under the same test conditions. It compares models on equal terms and does not predict a gas bill. The steps are set out in how the annual energy and cost figures are calculated.

The high draw pattern describes a larger household, or one where showers and laundry overlap. Among the 397 gas tankless models registered at that pattern, this unit ranks 45th lowest in energy use. Its registered maximum flow rate in gallons per minute is 4.2. The temperature rise that flow rate assumes is not stated in this data. For a home whose hot-water use sits well below the high pattern, this ranking is not the matching comparison. This model's figures at other draw patterns are not available here. To check other units registered in the same class, use the same-class replacement search by model number.

No running cost appears in this text, because it depends on your state's average residential gas price. Once you enter a ZIP, the page multiplies 178 therms by that price and shows the result in its own block. The same applies to the 4 therms gap: what it is worth depends on your rate, and it holds only at the test draw. You can run both in the cost calculator for your own ZIP. The installed-price range on this page is a modeled installed-cost range, shown with its own source and date. It is not a quote for this VESTA VRS-150, and the installed price for any given home is not known here.