How old is my Richmond water heater?

Serial number age decoder for Richmond tank water heaters: 5 format eras, the decode rule in plain English, transcribed tables, and the official lookup.

Serial number decoder for Richmond water heater

Serial no.

Type the serial from the data plate, not the model number. Nothing is sent anywhere; the tables are in this page.

Format example: 0804B10488

Richmond water heater serial numbers in the era not stated format encode the year as digits 3-4 (YY) and the month as digits 1-2 (MMYY prefix) (source: building-center.org).
Example: serial 0804B10488 decodes to August 2004.
Richmond water heater serial numbers in the era not stated format encode the year as digits 3-4 (YY = 2004) and the month as digits 1-2 (12 = December) (source: building-center.org).
Example: serial 1204D01234 decodes to December 2004.
Richmond water heater serial numbers in the era not stated format encode the year as digits 3-4 of the numeric part (YY) and the month as digits 1-2 of the numeric part (source: building-center.org).
Example: serial RU 0904B21710 decodes to September 2004.
Richmond's official lookup at richmondwaterheaters.com returns warranty / registration lookup.

Format eras

2010 to present VERIFIED
A#########digits 4-5 (20YY)
era not stated VERIFIED
####A#####digits 3-4 (YY)
era not stated VERIFIED
####A#####digits 3-4 (YY = 2004)
era not stated VERIFIED
AA ####A#####digits 3-4 of the numeric part (YY)
era not stated VERIFIED
AAAA ##########digits 3-4 of the numeric part (YY)

How to read the serial

2010 to present formatVERIFIED

Shape A######### · example A141511869 · confidence high

Year: digits 4-5 (20YY)
Week or month: WEEK = digits 2-3 (not month)
Plant: letter 1

Example: serial A141511869 decodes to week 14 of 2015.

Trap: Newer WWYY style: A141511869 = week 14 of 2015; plate prints Manufacture Date 31MAR2015. Order is reversed vs the MMYY styles - a value >12 in digits 2-3 signals this style.

Listed under Ruud water heaters in the source; Richmond is named in that format's family and the corporate link is an estimate, not a checked fact.

era not stated formatVERIFIED

Shape ####A##### · example 0804B10488 · confidence high

Year: digits 3-4 (YY)
Week or month: month = digits 1-2 (MMYY prefix)
Plant: letter at position 5

Example: serial 0804B10488 decodes to August 2004.

Trap: MMYY vs older 9-digit style (123451872: year = last 2 digits, week = 3rd-4th from last); also used on some older HVAC. Rheem's own site has no age page; only the warranty-verification tool.

Listed under Rheem in the source; Richmond is named in that format's family and the corporate link is an estimate, not a checked fact.

era not stated formatVERIFIED

Shape ####A##### · example 1204D01234 · confidence high

Year: digits 3-4 (YY = 2004)
Week or month: month = digits 1-2 (12 = December)
Plant: letter at position 5 (plant/line; table not published)

Example: serial 1204D01234 decodes to December 2004.

Trap: Identical to Rheem water-heater style (0804B10488 in formats.json Rheem WH rule); Richmond page says all Paloma-brand styles apply (also W291013412, CB5D302F..., OR177 M2807 00097, 123451872 = Rheem rules). Century by context.

era not stated formatVERIFIED

Shape AA ####A##### · example RU 0904B21710 / RHNG 0804P000036 / R 0804B10488 · confidence high

Year: digits 3-4 of the numeric part (YY)
Week or month: month = digits 1-2 of the numeric part
Plant: letter after the 4 date digits

Example: serial RU 0904B21710 decodes to September 2004.

Trap: = Rheem water heater MMYY rule (formats.json 0804B10488). Plate photo confirms RU 0904B21710 = MFG. DATE 09/2004. Prefix varies (R, RH, RHLN, RHNG, RU). Collides with American pre-2008 YYMM shape.

Listed under Ruud water heaters in the source; Richmond is named in that format's family and the corporate link is an estimate, not a checked fact.

era not stated formatVERIFIED

Shape AAAA ########## · example RHLN 0106534307 · confidence high

Year: digits 3-4 of the numeric part (YY)
Week or month: month = digits 1-2

Example: serial RHLN 0106534307 decodes to January 2006.

Trap: Plate photo: RHLN0106534307 with MFG. DATE 01/2006. All-numeric variant of the MMYY style.

Listed under Ruud water heaters in the source; Richmond is named in that format's family and the corporate link is an estimate, not a checked fact.

Where the data plate is on a water heater

The rating plate is a large label on the side of the tank near the top or beside the control. The serial is printed on it, often beside the model number and the ANSI standard line.

General guidance, not brand-specific: the owner's manual or the installer can point to the exact spot. See the data plate guide.

For scale only: the InterNACHI Standard Estimated Life Expectancy Chart for Homes lists Water Heater (conventional) at 6 to 12 years of expected service (nachi.org). That chart is a guideline, not a prediction for your unit.

Official lookup: the authority

Open the official Richmond 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

Richmond is treated as sharing Rheem's format because the source lists it in that family; the corporate relationship itself is an estimate.
Richmond is treated as sharing Ruud water heaters's format because the source lists it in that family; the corporate relationship itself is an estimate.
Identical to the Ruud/Rheem water heater styles: R 0804B10488 (MMYY + letter), RHNG 0804P000036 (tankless MMYY), 05.05-000021 (tankless YY.MM). No Richmond-specific rules needed.

Sources

https://www.building-center.org/rheem/
https://www.rheem.com/faq/official
https://www.building-center.org/richmond-hvac-age/
https://www.building-center.org/ruud-water-heater-age/
https://www.building-center.org/richmond-water-heater-age/
img: Ruud1-Water-Heater-Age.png, Ruud5-Water-Heater-Age.png
img: Ruud2-Water-Heater-Age.png
img: Ruud3-Water-Heater-Age.png
https://www.richmondwaterheaters.com/warranty/official