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Rheem Professional Water Heater Age by Serial Number — Free Lookup

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Enter the serial number from the rating plate (the silver data sticker on the upper side of the tank; on tankless units it is inside the cover on the right side). Works for Rheem, Ruud and Richmond — many Rheem plates also print the manufacture date directly as "MFG. DATE".

How Old Is Your Rheem Professional Water Heater?

Professional is Rheem's plumber-focused product line, and it uses the same serial date code as every other Rheem-built tank: month, then year, in the first four digits after any letter prefix. Enter your serial in the free decoder above for an instant answer, or follow the guide below to read it yourself.

Where to Find the Serial Number

Check the rating plate on the side of the tank — a sticker, usually in the upper half, that lists the model number and serial number together. The date lives in the serial, not the model number. If the sticker has faded, photograph it and boost the contrast; the first four digits after any prefix are all you need.

How the Rheem Professional Serial Format Works

Rheem encodes the date as MMYY — month first, then year — in the first four digits after any letter prefix:

Worked example — RH0906C27841:

  • RH = plant code (ignore)
  • 09 = September (month)
  • 06 = 2006 (year)
  • C and the remaining digits = production sequence
  • Result: manufactured in September 2006

Letter prefixes are plant codes. Serials often start with R, RH, RN, RHNG, or a single letter — none of these are part of the date. Skip them and read the first four digits you find.

Why Your Rheem Professional Water Heater's Age Matters

  • Warranty. Professional tanks carry 6- to 12-year warranties counted from the manufacture date, not the install date — and they often sit in a wholesaler's warehouse before installation. The serial is the only way to know when the clock started.
  • Lifespan. Tank water heaters average 8–12 years of service. Past that, internal corrosion makes tank failure — and a flooded floor — far more likely.
  • Replacement planning. A unit past 10 years is on borrowed time. Knowing the date lets you shop for a replacement calmly instead of during an emergency.

Sources

Serial format verified against the InterNACHI water heater dating chart and InspectApedia's Rheem age decoder; the Professional line label is documented in the same sources' Rheem brand lists.

Frequently asked questions

What is a Rheem Professional water heater?
Professional is Rheem's plumber-focused product line, sold through professional plumbing channels rather than big-box retail. The label reads "Rheem Professional" on the rating plate, but the serial number uses the exact same date code as every other Rheem-built unit.
How do I tell the age of a Rheem Professional water heater from the serial number?
After any leading letter prefix, the first two digits are the month and the next two are the year. For example, serial RH0906C27841 means September 2006 — month 09, year 06. Letters before the digits are plant codes; the date always follows them.
Where is the serial number on a Rheem Professional water heater?
On the rating plate — a sticker on the side of the tank, usually in the upper half, that lists the model and serial numbers together. Professional line plates also show the tank warranty years; the serial is the only way to get the true manufacture date.
Do Professional line tanks last longer than retail Rheems?
Professional tanks are built to the same standard as other Rheem units, with the main difference being warranty length (often 6–12 years depending on the model). Actual service life still averages 8–12 years and depends far more on water quality and maintenance than on the product line.
My Rheem Professional serial starts with letters. How do I read it?
Leading letters are plant codes such as R, RH, RN, or RHNG — not part of the date. Skip them and read the first four digits you find as month and year: RH0906C27841 decodes to September 2006.