How old is my Reliance unit?
Reliance is part of A.O. Smith Corp. 8 serial formats sourced across water heater.
Serial number decoder for Reliance
Type the serial from the data plate, not the model number. Nothing is sent anywhere; the tables are in this page.
Format example: 1210A002243
- Reliance water heater serial numbers in the 2008 to present format encode the year as digits 1-2 (YY) after optional leading S and the week as digits 3-4 (source: building-center.org).
- Example: serial 1210A002243 decodes to week 10 of 2012.
- Reliance water heater serial numbers in the before 2010 format encode the year as digits 2-3 = FISCAL year (Oct 1 - Sep 30); for A/B/C (Oct-Dec) subtract 1 for calendar year (A91 = Oct 1990) and the month as letter 1, fiscal table A=Oct..M=Sep (I skipped) (source: building-center.org).
- Example: serial L92441351 decodes to August 1992.
- Reliance water heater serial numbers in the before 2010 format encode the year as digits 2-3 = fiscal year (see style 1) and the month as letter 1, fiscal table A=Oct (source: building-center.org).
- Example: serial C91A136750 decodes to December 1991.
- Reliance's official lookup at reliancewaterheaters.com returns warranty / registration lookup.
Decoder pages by product
Format eras
- before 2010 VERIFIED
A########Water Heater - before 2010 VERIFIED
A##A######Water Heater - before 2010 VERIFIED
AA########Water Heater - before 2010 VERIFIED
A##A######Water Heater - 2008 to present VERIFIED
####A######Water Heater, Heat Pump Water Heater, Tankless Water Heater - 2008 to present VERIFIED
####A######Water Heater - before 2008 VERIFIED
AA##A######Water Heater - 1970 to 1979 VERIFIED
A##-A-##-######Water Heater
Official lookup: the authority
Open the official Reliance lookup takes serial number; returns warranty / registration lookup; URL verified live
This site is a reference built from published tables. The manufacturer's own lookup wins whenever the two disagree.
What we could not confirm
- Reliance is treated as sharing A.O. Smith's format because the source lists it in that family; the corporate relationship itself is an estimate.
- The before 2010 format is documented but not decodable here: example AJ03123456 does not decode with the derived engine.
- Style 4 (1211A018632) = A.O. Smith YYWW. Styles 1-3 use a FISCAL-year month table (A=Oct) unlike State/AO Smith letter styles.
Sources
- https://www.building-center.org/a-o-smith/
- https://www.building-center.org/reliance-water-heater-age/
- img: RELIANCE-1-WH-Serial-Number.jpg (last update Jul-2012)
- img: RELIANCE-2-WH-Serial-Number.jpg
- img: RELIANCE-3-WH-Serial-Number.jpg
- img: Reliance-Water-Heater-Style-4.png
- https://www.reliancewaterheaters.com/support/warranty-verification.htmlofficial