{"schemaVersion":"1.0","interfaceVersion":"0.21.0","reviewedAt":"2026-08-13","mode":"read-only-reference","inputGuidance":{"required":"Brand plus at least one of complete model or serial number.","preferred":"Provide both complete model and serial exactly as printed on the rating label; they answer independent questions.","unsupportedBehavior":"Return unsupported, invalid, ambiguous, unavailable, or unresolved rather than coercing an unknown format or filling one evidence gap with another check."},"serialNormalization":{"brand":"Lowercase the supplied brand, replace punctuation other than periods with spaces, collapse spaces, then apply only the aliases listed for a supported family.","serial":"Uppercase the supplied serial and remove spaces and hyphens before testing a listed cleanedPattern.","yearResolution":"For MMYY and YYWW families, use the current century only when the two-digit year is no later than one year after the current year; otherwise use the prior century. Reject resolved years before 1960 or more than one year in the future."},"serialFamilies":[{"id":"rheem-mm-yy","canonicalBrand":"Rheem","normalizedBrand":"rheem","aliases":["Rheem","Ruud"],"formats":[{"id":"mmyy-plant-letter-five-digits","label":"MMYY + plant letter + five digits","cleanedPattern":"^[0-9]{4}[A-Z][0-9]{5}$","examples":[{"serial":"1209D01234","interpretation":"December 2009"}],"decodedFields":["manufacture month 01 through 12","two-digit manufacture year"],"validation":"Month must be 01 through 12; the resolved year must be from 1960 through one year after the current year.","source":{"title":"How to Locate and Read Your Rheem Water Heating Serial Numbers","publisher":"Rheem","url":"https://www.rheem.com/how-to-locate-and-read-your-rheem-water-heating-serial-numbers/","accessedAt":"2026-08-12"}}],"ambiguity":"No date-cycle ambiguity is returned after the bounded two-digit-year resolution rule.","limitations":["Other Rheem and Ruud serial families may exist and are not coerced into this format."]},{"id":"ao-smith-yy-ww","canonicalBrand":"A. O. Smith","normalizedBrand":"ao-smith","aliases":["A. O. Smith","A.O. Smith","A O Smith","AO Smith","AOSmith"],"formats":[{"id":"yyww-numeric-sequence","label":"YYWW followed by a numeric sequence","cleanedPattern":"^[0-9]{10,14}$","examples":[{"serial":"1719106145074","interpretation":"Week 19 of 2017"}],"decodedFields":["two-digit manufacture year","production week 01 through 53"],"validation":"The resolved year must be from 1960 through one year after the current year; week must be 01 through 53.","source":{"title":"Service and Warranty Guide","publisher":"A. O. Smith","url":"https://assets.hotwater.com/damroot/Original/10009/ServiceWarrantyGuide.pdf","accessedAt":"2026-08-13"}},{"id":"yyww-plant-letter-six-digits","label":"YYWW + manufacturing-location letter + six digits","cleanedPattern":"^[0-9]{4}[A-Z][0-9]{6}$","examples":[{"serial":"1203M001714","interpretation":"Week 3 of 2012"}],"decodedFields":["two-digit manufacture year","production week 01 through 53","manufacturing-location letter"],"validation":"The resolved year must be from 1960 through one year after the current year; week must be 01 through 53.","source":{"title":"Service and Warranty Guide — plant-letter serial example","publisher":"A. O. Smith / State Water Heaters","url":"https://sr.statewaterheaters.com/documentlibrary/warranty/ServiceWarrantyGuide_R1n.pdf","accessedAt":"2026-08-13"}}],"ambiguity":"No date-cycle ambiguity is returned after the bounded two-digit-year resolution rule.","limitations":["Older, tankless, and alternate A. O. Smith formats remain unsupported."]},{"id":"state-yy-ww","canonicalBrand":"State","normalizedBrand":"state","aliases":["State","State Water Heater","State Water Heaters"],"formats":[{"id":"yyww-numeric-sequence","label":"YYWW followed by a numeric sequence","cleanedPattern":"^[0-9]{10,14}$","examples":[{"serial":"1719106145074","interpretation":"Week 19 of 2017"}],"decodedFields":["two-digit manufacture year","production week 01 through 53"],"validation":"The resolved year must be from 1960 through one year after the current year; week must be 01 through 53.","source":{"title":"Service and Warranty Guide","publisher":"A. O. Smith","url":"https://assets.hotwater.com/damroot/Original/10009/ServiceWarrantyGuide.pdf","accessedAt":"2026-08-13"}},{"id":"yyww-plant-letter-six-digits","label":"YYWW + manufacturing-location letter + six digits","cleanedPattern":"^[0-9]{4}[A-Z][0-9]{6}$","examples":[{"serial":"1203M001714","interpretation":"Week 3 of 2012"}],"decodedFields":["two-digit manufacture year","production week 01 through 53","manufacturing-location letter"],"validation":"The resolved year must be from 1960 through one year after the current year; week must be 01 through 53.","source":{"title":"Service and Warranty Guide — plant-letter serial example","publisher":"A. O. Smith / State Water Heaters","url":"https://sr.statewaterheaters.com/documentlibrary/warranty/ServiceWarrantyGuide_R1n.pdf","accessedAt":"2026-08-13"}}],"ambiguity":"No date-cycle ambiguity is returned after the bounded two-digit-year resolution rule.","limitations":["Only the two forms in the manufacturer-family service guides are supported; alternate State formats remain unsupported."]},{"id":"american-water-heaters-yy-ww","canonicalBrand":"American Water Heaters","normalizedBrand":"american","aliases":["American","American Water Heater","American Water Heaters"],"formats":[{"id":"yyww-numeric-sequence","label":"YYWW followed by a numeric sequence","cleanedPattern":"^[0-9]{10,14}$","examples":[{"serial":"1719106145074","interpretation":"Week 19 of 2017"}],"decodedFields":["two-digit manufacture year","production week 01 through 53"],"validation":"The resolved year must be from 1960 through one year after the current year; week must be 01 through 53.","source":{"title":"Service and Warranty Guide","publisher":"A. O. Smith","url":"https://assets.hotwater.com/damroot/Original/10009/ServiceWarrantyGuide.pdf","accessedAt":"2026-08-13"}},{"id":"yyww-plant-letter-six-digits","label":"YYWW + manufacturing-location letter + six digits","cleanedPattern":"^[0-9]{4}[A-Z][0-9]{6}$","examples":[{"serial":"1203M001714","interpretation":"Week 3 of 2012"}],"decodedFields":["two-digit manufacture year","production week 01 through 53","manufacturing-location letter"],"validation":"The resolved year must be from 1960 through one year after the current year; week must be 01 through 53.","source":{"title":"Service and Warranty Guide — plant-letter serial example","publisher":"A. O. Smith / State Water Heaters","url":"https://sr.statewaterheaters.com/documentlibrary/warranty/ServiceWarrantyGuide_R1n.pdf","accessedAt":"2026-08-13"}}],"ambiguity":"No date-cycle ambiguity is returned after the bounded two-digit-year resolution rule.","limitations":["American Standard is a separate unsupported brand.","Older, tankless, and alternate American Water Heaters formats remain unsupported."]},{"id":"bradford-white-letter-cycle","canonicalBrand":"Bradford White","normalizedBrand":"bradford-white","aliases":["Bradford White","BradfordWhite"],"formats":[{"id":"year-letter-month-letter","label":"Year letter + month letter + alphanumeric sequence","cleanedPattern":"^[A-HJ-NPSTW-Z][A-HJ-M][A-Z0-9]{4,}$","examples":[{"serial":"YE123456","interpretation":"May 1982, 2002, or 2022 when evaluated in 2026"}],"decodedFields":["repeating manufacture-year letter","manufacture-month letter"],"validation":"Return only candidate months that are not in the future at evaluation time.","source":{"title":"How to read the serial number date code reference chart","publisher":"Bradford White","url":"https://www.bradfordwhite.com/bw-faq/how-to-read-the-serial-number-date-code-reference-chart/","accessedAt":"2026-08-12"}}],"ambiguity":"Bradford White year letters repeat every 20 years, so every past candidate remains possible unless label or installation context resolves the cycle.","limitations":["Do not choose one 20-year cycle without additional evidence."]}],"explicitlyUnsupported":[{"brand":"American Standard","normalizedBrand":"american standard","reason":"American Standard is a separate brand and is never normalized to American Water Heaters. No sufficiently narrow American Standard decoder is published here."}],"modelCatalog":{"evidenceRole":"Current U.S.-market ENERGY STAR certified model identity.","acceptedIdentifier":"Complete brand and complete model number.","matchRule":"Exact normalized brand and complete model only. ENERGY STAR rows containing model wildcards are never promoted to an exact match.","statuses":["exact-match","no-match","ambiguous","unavailable","not-run"],"noMatchMeaning":"No match does not prove that a model is invalid, uncertified, or absent from historical data.","privacy":"The server fetches the same bounded current dataset and matches locally; entered brand and model values are not added to the ENERGY STAR request URL.","source":{"title":"ENERGY STAR Certified Water Heaters dataset and API","publisher":"U.S. EPA ENERGY STAR","url":"https://data.energystar.gov/Active-Specifications/ENERGY-STAR-Certified-Water-Heaters/pbpq-swnu","accessedAt":"2026-08-13"}},"recallScreening":{"evidenceRole":"Candidate notices from the current official U.S. CPSC water-heater feed.","acceptedIdentifiers":["brand","complete model number"],"matchRule":"A complete normalized model text match is stronger than brand-only phrase evidence. The complete official notice and equipment label control applicability.","commonWordBrandRule":"State and American require explicit manufacturer evidence such as State Water Heaters, State Industries, or American Water Heater; generic uses of state, states, or American are ignored.","statuses":["candidates-found","none-found","unavailable"],"emptyResult":"No candidates found is not an all-clear, proof of safety, or proof that the unit has never been recalled.","source":{"title":"CPSC Recalls API","publisher":"U.S. Consumer Product Safety Commission","url":"https://www.cpsc.gov/Recalls/CPSC-Recalls-Application-Program-Interface-API-Information","accessedAt":"2026-08-12"}},"globalLimitations":["Serial decoding estimates manufacture timing; it does not establish installation date, condition, remaining life, warranty, or safety.","Model identity, serial-date interpretation, and recall screening are independent checks; one check never fills a gap in another.","Only the serial families listed in this directory are supported. Unlisted brands and alternate formats remain unsupported.","Do not use this reference or a lookup result for emergency diagnosis."],"privacy":{"acceptedInputs":[],"writesPerformed":false,"storedData":[],"statement":"This reference endpoint accepts no input, performs no lookup, creates no history, and contains no provider, customer, account, or configuration data."}}