How we build each page
Source hierarchy
We use a tiered source system. When values conflict between sources, the higher-tier source wins.
DOE-validated performance metrics: UEF, first hour rating, annual energy use, draw pattern. This is the federal test record.
PDF spec sheets and engineering documents. Dimensions, electrical requirements, venting specs, warranty terms.
Brand websites. Supplemental specs, feature details, WiFi capability, operating modes.
Used only to fill gaps in dimensions or features not published elsewhere. Always tagged as "Retailer listing" or "Distributor listing" in the source block.
Every data field on every model page carries a source tag. When a field comes from a lower-tier source, the source block on the page makes that visible.
Publish criteria
A model page is only generated when the record passes all required checks. Models that fail any check remain in the database but do not appear on the site.
- Brand and model number identified
- Type and fuel source classified
- UEF (Uniform Energy Factor) present
- Storage capacity or flow rate present
- Height and width dimensions present
- Warranty data present (tank or parts)
- Depth and weight
- Breaker size and wire gauge
- Sound level (heat pumps)
- WiFi capability
- Amazon ASIN (for affiliate link)
- Indoor/outdoor classification
Cost calculations
Annual operating costs use the model's DOE-tested annual energy consumption multiplied by the U.S. average residential energy rate from the Energy Information Administration (EIA). State-specific pages use state-level EIA rates.
These are estimates based on standardized test conditions, not guarantees of actual household costs. Your home's usage pattern, inlet water temperature, climate, and utility rate structure will affect real-world costs.
Rankings
When we rank models, rankings are within a specific class: same type and similar capacity range. We rank on published specifications only: UEF, height, first hour rating, and flow rate.
We do not use subjective scoring, user reviews, or editorial judgment. Tied values receive the same rank. Classes with fewer than 8 models do not show negative rank badges to avoid overstating the significance of small-sample rankings.
What we do not promise
We do not promise that every page is complete, current, or fit for your project. Rebate programs, legal standards, warranty terms, and product details can change after publication. The site is provided for informational use only and should not be treated as a substitute for live manufacturer documents, permits, or professional advice.
Manufacturer names, marks, and model numbers belong to their respective owners. We use them only to identify the products being referenced.
Corrections
If you find an error in our data, email corrections@ratingplate.com with the model number, the correct value, and the source document so we can verify and update.