§ 05 Equipment age
How old is my Rheem water heater?
On current tank water heaters the serial is one letter, then two digits for the week, two digits for the year, then the unit number.
Serial diagram · Rheem water heaters
Type the serial
On current tank water heaters the serial is one letter, then two digits for the week, two digits for the year, then the unit number.
Manufacturer-documented format
The Rheem date code
“All you need to know is your heater’s serial number. (The page runs Rheem’s age service; dates below are what it returned.)”
| Serial | Made | How | From |
|---|---|---|---|
| M461914345 | November 2019 | Rheem’s age service returned 11/14/2019: week 46 of 2019. | Returned by the manufacturer’s tool |
| Q291612345 | July 2016 | Returned 07/15/2016: week 29 of 2016. | Returned by the manufacturer’s tool |
| Q522012345 | December 2020 | Returned 12/18/2020: week 52 of 2020. | Returned by the manufacturer’s tool |
| Q102412345 | March 2024 | Returned 03/12/2024: week 10 of 2024. | Returned by the manufacturer’s tool |
Older Rheem serials and HVAC equipment use other layouts. Confirm with Rheem’s own tool (linked).
Lifespan
How long a water heater lasts
About 15 years on average. An average across tank water heaters, from DOE’s survival analysis of national survey data. Hard water, sediment and a failed anode shorten it; it is not a guarantee.
“DOE estimates the average product lifetime to be around 15 years for storage water heaters.”