Westinghouse HW180

The 206 therms figure does not come directly from the registry. This site calculated it from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.82 for this model. The other input is the DOE test's daily hot-water draw for the high draw pattern. Both come from DOE's Compliance Certification Database (CCD), retrieved 2026-09-19. The figure therefore describes the federal test's daily draw, not the use of any real household. A home that uses more or less hot water than the test will use a different amount of gas. That amount is not available on this page. The steps behind the figure are explained in how the annual cost is calculated.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. The rank given above puts the Westinghouse HW180 in the second-highest quarter of its class for energy use. More than half of the gas tankless units tested at this draw pattern use less energy under the same test. The registry lists this model's maximum flow rate in gallons per minute as 4.2. Hot-water demand above that rate is outside the unit's listed maximum flow. The data here does not show how the unit performs above that flow. To check other gas tankless units rated at the same draw pattern, use the tool to find a same-class replacement by model number.

This text gives no running cost. The cost of 206 therms of natural gas depends on your state's average residential gas price, so the page calculates it from your ZIP. Enter it in the cost calculator for your own ZIP to see that figure. The 24 therms gap to the class median measures energy, not cost. At any one gas price, the cost gap between this model and the class median follows from that energy difference. The installed-cost range in its own block is a modeled range with its source and date, not a quote. Energy use at a daily draw different from the federal test is not available here.