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How old is my Ruud Water Heaters water heater?

Serial number age decoder for Ruud Water Heaters tank water heaters: 4 format eras, the decode rule in plain English, transcribed tables, and the official lookup.

Serial number decoder for Ruud Water Heaters water heater

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

Format example: RU 0904B21710

Format eras

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; Ruud Water Heaters is named in that format's family and the corporate link is an estimate, not a checked fact.

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; Ruud Water Heaters 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; Ruud Water Heaters 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; Ruud Water Heaters 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 Ruud Water Heaters 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

Sources

Ruud Water Heaters tankless water heater Rheem Manufacturing family All water heater brands Guides