VESTA VX 9

The 176 therms figure was computed by this site. It was not taken from the registry. It starts from the registry's UEF, the ratio of hot water delivered to energy used. It then applies the DOE test's daily hot-water draw for the high draw pattern. For the VESTA VX 9, the registered UEF is 0.96. The inputs come from the DOE CCD, retrieved 2026-09-19. The 397 gas tankless models registered at the same draw pattern form its class. Within that class, this unit ranks 12th lowest in energy use. Its gap to the class median is 6 therms a year under the same test conditions. The page on how the annual energy and cost figures are calculated sets out each step.

The high draw pattern describes a larger household, or one where showers and laundry overlap. The 176 therms figure holds only at that pattern's test draw. A home that draws more or less hot water each day will use a different amount. That amount is not available in the data. The unit's registered maximum flow rate in gallons per minute is 6. Whether that rate covers overlapping showers in a given home depends on its fixtures, which this page does not measure. To compare other gas tankless units at the same draw pattern, use the selector by fuel, space and size. To check a unit already in place, you can find a same-class replacement by model number.

The running cost does not appear in this text because it depends on your state's average residential gas price. The page computes it from your ZIP and applies it to 176 therms a year at the high draw pattern. Two readers in different states will see different costs for the same unit. What the 6 therms gap to the class median means in cost also depends on your rate. You can rerun the figure in the cost calculator for your own ZIP. The installed-price block on this page shows a modeled range with its own source and date. It is not a quote.