AMERICAN PETX-40 1**

The figure of 3,531 kWh is a computed value, not a registry entry. This site combined the registry's UEF, the ratio of hot water delivered to energy used, which is 0.92 for this model, with the daily hot-water draw of the federal test for the medium draw pattern. The condition is the test draw, so a household that uses more or less hot water will see a different total. The data source is DOE CCD, retrieved 2026-09-19. The calculation steps are set out in the methodology for water heater costs.

Against its class, the model sits at the median. Its 3,531 kWh equals the class median of 3,531 kWh, a difference of 0 kWh, and it ranks 213th lowest of 426 electric tank models registered at the medium draw pattern. The figure fits a household whose hot-water use resembles the medium pattern, a typical multi-person household on a busy morning. It does not describe a household with heavier use, and this page has no annual figure for other draw patterns. Capacity is separate from energy use. The first hour rating, the gallons of hot water available in the first hour from a full tank, is 64 gallons. The rated volume is 37 gallons. The water heater selector filters by fuel, space and size.

The running cost is not stated here because it depends on the electricity tariff the reader pays. With 3,531 kWh a year at the medium draw pattern, the cost is that quantity multiplied by the reader's own rate per kilowatt-hour. The cost calculator applies the utility rate for the reader's ZIP to this figure. The modeled installed-cost range appears in its own block on the page with its source and date, and it is a modeled range, not a quote. To look for a same-class alternative, find a replacement by model number starting from PETX-40 1**. The annual figure is a calculation at the federal test draw, not a measurement in any home.