Lowest Operating Cost: Water heaters

Ranked by estimate. Operating cost is an estimate, computed from each model's measured annual energy use at the EIA U.S. national-average residential electricity rate (18.56 ¢/kWh, March 2026). Your actual cost depends on your local utility rate and how you use the appliance.

The Friedrich PROH40 T2 FD400-15 ranks as the lowest-operating-cost water heater in the dataset, with an estimated annual operating expense of $119.34 based on 643 kilowatt-hours per year and the national-average electricity rate. This ranking reflects certified models sorted solely by energy consumption and operating cost, with no payment or consideration applied to influence placement.

Operating cost represents only one dimension of a water heater purchase decision. Capacity, available features, reliability track record, and upfront purchase price each carry independent weight and are not reflected in this energy-efficiency ranking. Prospective buyers should treat this as one lens—the energy-efficiency perspective—and balance it against specifications, durability ratings, warranty terms, and total cost of ownership. This comparison provides a spec-and-cost foundation rather than a comprehensive buying recommendation.

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