Rheem® Water age

How to determine the date of production/manufacture or age of Rheem® brand Water Heater Systems.

Water heaters in general have an average estimated useful service life of 10-12 years, though water quality, routine upkeep/maintenance, and location of the water heater will all play critical roles in the longevity of these systems.

Parent Company: Independent subsidiary of Paloma Industries

The date of production/manufacture or age of A.O. Smith brand Water Heater equipment can be determined from the serial number located on the rating data plate.

Example serial number styles/formats found:

→Style 1: R 0884B10488 (Serial Number may begin with other prefix - i.e. R; RN; RNG; RHNG; etc.)

→Style 2: RHLN 0106534307 (Serial Number may begin with other prefix - i.e. R; RN; RNG; RHLN; etc.)

→Style 3: A141511869

→Style 4: D1114A441408265A

→Style 5: RHNG 0804P000036 (Serial Number begins with a prefix - i.e. R; RN; RNG; RHNG; etc.)

→Style 6: 05.05-000021 (Tankless Water Heater)

→Style 7: RHUN M181401735 (Serial Number may begin with a prefix - i.e. R; RN; RNG; RHNG; etc.)

Legend: Year is RED; Month is GREEN; Week is BLUE

→Style 1: R 0804B10488

CAUTION: Prefix can be R; RH; RHLN; RHNG; RU; etc.

Year of manufacture can be determined by using the 3^rd & 4^th digits of the serial number (after letter prefixes)

Month of manufacture can be determined by using the 1st & 2nd digits of the serial number (after letter prefixes)

Rheem Water Heater Age – Serial Number – Style 5

→Style 2: RHLN 0106534307

CAUTION: Prefix can be R; RH; RHLN; RHNG; RU; etc.

Year of manufacture can be determined by using the 3^rd & 4^th digits of the serial number (after letter prefixes)

Month of manufacture can be determined by using the 1st & 2nd digits of the serial number (after letter prefixes)

NOTE: The specific manufacture date is often included on the data rating plate with the serial number and model number.

Rheem Water Heater Age – Serial Number – Style 2

→Style 3: A141511869

Year of manufacture can be determined by using the 3^rd & 4^th digits of the serial number (after letter prefix)

Week of manufacture can be determined by using the 1st & 2nd digits of the serial number (after letter prefix)

NOTE: The specific manufacture date is often included on the data rating plate with the serial number and model number.

Rheem Water Heater Age – Serial Number – Style 3

→Style 4: D1114A441408265A

Year of manufacture can be determined by using the 3^rd & 4^th digits of the serial number (after letter prefix)

Month of manufacture can be determined by using the 1st & 2nd digits of the serial number (after letter prefix)

NOTE: The specific manufacture date is often included on the data rating plate with the serial number and model number.

Rheem Water Heater Age – Serial Number – Style 4

→Style 5: 05.05-000021

Year of manufacture can be determined by using the 1^st & 2^nd digits of the serial number

Month of manufacture can be determined by using the 3^rd & 4^th digits of the serial number

Rheem Water Heater Age – Serial Number – Style 6

→Style 7: RHUN M181401735

CAUTION: Prefix can be R; RH; RHLN; RHNG; RU; etc.

CAUTION: This style also includes an additional letter prefix for factory code.

Year of manufacture can be determined by using the 3^rd & 4^th digits of the serial number (after letter prefixes)

Week of manufacture can be determined by using the 1st & 2nd digits of the serial number (after letter prefixes)

NOTE: The specific manufacture date is often included on the data rating plate with the serial number and model number.

Rheem® History¹

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Every effort is undertaken to offer you correct and concise information to assist you in determining the age or manufacture date of water heating equipment. Users relying on this information do so at their own risk.

Page last updated: 08/30/2023

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