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)Cand 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.