Ruud Water Heater Age by Serial Number
Ruud water heaters use two main serial-number date structures. Through August 2012, four date digits read as MMYY: two digits for the month followed by two digits for the year. For example, split serial number 1109D01234 as 11 | 09 | D | 01234. The code 11 means November, 09 means 2009, D identifies the plant line, and 01234 is the unit sequence.
After August 2012, most Ruud water-heater serial numbers begin with a plant letter followed by WWYY. Split M301703203 as M | 30 | 17 | 03203: M is the plant code, 30 is the production week, 17 means 2017, and 03203 is the unit sequence. The Ruud serial number alone gives Appliage enough information to estimate the age. The model number is not needed.
Appliage decodes two Ruud water heater date structures. From September 2012, a plant letter comes first and the four digits after it give the production week and then the year, so M301703203 is week 30 of 2017. Through August 2012, the first four date digits give the month and then the year, so 1109D01234 is November 2009. Both structures are covered under Ruud Water Heater Age Rules below.
Shape decides which structure applies. Without a letter in front of the four date digits, the month and year structure applies. When a plant letter comes first, the two digits after it are the production week and the next two are the year, and Appliage uses that structure whenever the week and year land after August 2012.
Ruud Water Heater Serial Number Introduction
| Ruud structure | Serial arrangement | Date fields | Example |
|---|---|---|---|
| Through August 2012 | MM | YY | plant/sequence, sometimes with letters before the date | Month first, then two-digit year | 1109D01234 = November 2009 |
| After August 2012 | Plant letter | WW | YY | sequence | Production week first, then two-digit year | M301703203 = week 30 of 2017 |
Older Ruud MMYY Structure
| Field | Meaning | Example from 1109D01234 |
|---|---|---|
| MM | Month from 01 through 12 | 11 means November |
| YY | Two-digit year | 09 means 2009 |
| Remaining characters | Plant line and unit sequence | D01234 identifies the individual water heater and does not influence the date |
Some older Ruud serial numbers place letters before the MMYY field. The date still comes from four consecutive digits that form a valid month and year. For example, 0197 means January 1997 and 0804 means August 2004.
Later Ruud Plant-Letter + WWYY Structure
| Field | Meaning | Example from M301703203 |
|---|---|---|
| Opening letter | Manufacturing plant | M identifies the plant |
| WW | Production week from 01 through 53 | 30 means week 30 |
| YY | Two-digit year | 17 means 2017 |
| Remaining digits | Unit sequence | 03203 identifies the individual water heater and does not influence the date |
The plant letter tells Ruud where the water heater was manufactured and helps with production tracing. It does not provide the production week or year. A 2016 federal recall shows this newer structure on serial numbers beginning with A, M, or Q followed by week-year codes from 2014 and 2015.
Ruud Serial Numbers Appliage Cannot Find the Age
Appliage cannot find the age when an older serial has a month outside 01–12 or when a newer serial has a production week outside 01–53. A serial that matches neither structure needs a different date coding method.
Ruud air conditioners, furnaces, and heat pumps use HVAC serial systems, not the water-heater structures on this page. Select the matching Ruud product category before decoding the serial number.
Why Ruud Uses Rheem Water-Heater Structures
Ruud water heaters are part of the Rheem Water Heating family, and the two brands use the same older MMYY and later plant-letter-plus-WWYY structures. The Rheem water heater age lookup explains the same two readings on Rheem-branded tanks.
Sources
- Rheem serial number label instructions. Rheem explains the month, year, factory and unit sequence on the label.
- Rheem water heater age lookup. The examples start with a factory letter, followed by the week and year.
- Rheem water heater warranty procedure. Rheem changed from month then year to week then year after August 2012.
- CPSC: Rheem water heater recall (16-177). The notice pairs A, M and Q prefixes with production weeks in 2014 and 2015.
- CPSC: Rheem and Ruud tankless water heater recall (07-108)
For other brands, see our appliance serial number lookup.