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Water heaters date-code guide

Rheem Water Heaters serial number lookup

Many Rheem water-heater serials place a month/year code near the beginning, sometimes after a plant letter. The decoder validates both month and week variants.

Parent
Rheem Manufacturing
Common code
After an optional plant letter, four digits commonly encode month/year; some lines use week/year.
Reviewed
August 8, 2026

Instant equipment lookup

Decode the manufacturing date

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Equipment type

Using After an optional plant letter, four digits commonly encode month/year; some lines use week/year.

Type exactly what is printed. Spaces and dashes are ignored.

Optional: add model number for capacity cluesAdd model

Model decoding is labeled as a clue unless the exact format is documented.

No signupNo uploadNo serial-number tracking

EQUIPMENT DATA
MODEL24ABC636A003
SERIAL5019X30312
WeekYear

See exactly how the code was read

SerialAtlas highlights the date characters, names the matching rule, and shows alternative interpretations when the code is ambiguous.

  • Current age calculated automatically
  • Confidence and rule source shown
  • Optional model-capacity clue

Evidence-led route update

Rheem Water Heaters date-code evidence

If you need to estimate a Rheem water heater’s manufacture age, first identify whether the serial has an optional plant letter.

Keep the Rheem tank and tankless interpretations visible

After an optional plant letter, four digits commonly encode month/year; some lines use week/year. The verified Rheem water-heater family can read month/year after a plant letter and can expose a week/year alternative for some product families. A result that remains ambiguous is intentional. The verified Rheem water-heater family can place month/year after an optional plant letter and can expose a week/year alternative. The product type on the rating plate determines which candidate deserves follow-up.

Worked example: M092504723

M092504723 — The primary documented read is September 2025; the decoder keeps another plausible interpretation visible so the label and equipment era can resolve it.

When a Rheem water-heater result remains ambiguous

Do not collapse two plausible dates into one warranty or replacement claim. Retain every candidate, compare the model and label era, and use Rheem residential water-heating support for the official answer.

Model number vs. serial number

Use the Rheem model for tank, heat-pump, or tankless context and the serial for date candidates; provide both to support. Use the tank or tankless rating plate, then retain the model number and product type for the official manufacturer check.

Limits and official support

Rheem-family serials can support more than one plausible interpretation. If the result affects warranty, registration, parts, safety, or replacement decisions, use the complete model and serial with the manufacturer or a qualified professional. SerialAtlas is an independent reference, not an official warranty lookup or warranty coverage decision.

Open Rheem Water Heaters support route

How to read a Rheem Water Heaters serial number

After an optional plant letter, four digits commonly encode month/year; some lines use week/year. SerialAtlas removes spacing and punctuation, then applies only the documented rule families mapped to Rheem Water Heaters. The lookup remains in the browser.

Try this documented-style exampleM092504723Load example

Equipment covered

  • gas tank water heaters
  • electric tank water heaters
  • heat-pump water heaters
  • tankless water heaters

Commercial, imported, very old, specialty, and private-label equipment can use a different code. Confirm the full rating plate before accepting a result.

Where to find the rating plate

  • Upper or lower side of the tank jacket
  • Near the gas control valve on gas models
  • Behind an electrical access panel
  • Side or bottom edge of a tankless cabinet

Why more than one date can appear

Two-digit years and repeating letter cycles can point to more than one era. SerialAtlas ranks the plausible dates but keeps materially different alternatives visible. Label design, refrigerant, installation records, and product literature can resolve the era.

Source and verification

Inspector Handbook open reference data (CC BY 4.0). Independently implemented and reviewed August 8, 2026.

Open reference source

What this result does not prove

A manufacture date is not an installation date, warranty decision, recall match, condition assessment, or replacement recommendation. Confirm high-stakes decisions with the manufacturer or a qualified professional.