Water heaters — United States
What the DOE CCD has on file for this category, and how this site turns it into a running cost.
What is in scope
Every electric storage, gas storage, tankless (gas and electric) and heat pump water heater a manufacturer has on file with the DOE Compliance Certification Database is in scope here -- not a shortlist of popular models. A row in that registry is a (basic model × individual model) pair, not a model on its own; resolved to basic models, the last pull found 2,288 in this category, as of 2026-09-10.
Heat pump water heaters are not a separate filing type in that registry. They are a segment computed from the Uniform Energy Factor (UEF) a model files -- the ratio of hot water delivered to energy used. Where a page on this site describes one, it says which UEF threshold it used, because that threshold, like every other figure here, comes from the registry rather than from us.
What a page carries
A model page states its filed UEF and draw pattern, the annual running cost computed from them and the tariff your own utility publishes, and a typical installed-cost range -- each figure carrying the registry (or dataset) it came from and the date it was pulled. Two models with different draw patterns are never ranked against each other on UEF alone; the methodology page for this category explains why, and what this site does instead.
Model pages are published one registry pull at a time rather than all at once, so the
live count for this category on a given day can be smaller than the 2,288 above.
The current count is machine-readable at /us/home/water-heaters/index.json.
Not published yet
What is missing: filtered and ranked lists ("quietest", "most efficient for a given household"), model-to-model comparisons, cost calculators, and incentive-eligibility pages for this category.
Why: a ranked list needs a sorting metric that is measured, not assumed, and the sorting engine for it has not shipped; a comparison page needs the reliability-gap disclosure this site requires before it publishes one; the others each wait on their own not-yet-built page type.
What is here instead: the scope and methodology above, so each of those, when it ships, can be checked against what this page already promised.