Rheem HVAC Age: Serial Number Decoding for AC, Furnace, Air Handlers & Heat Pump

How old is my Rheem? Does a Rheem serial number tell you its age?

Yes – the serial number can be used to tell the Rheem age of unit.

How to Read a Rheem Serial Number

Quick answer: For most Rheem models and all those made recently, the serial number begins with a letter followed by 9 numbers.

The first two numbers after the letter represent the week of the year, 1 through 52. The second two numbers (numbers 3 and 4) are the year.

So, W2210 represents the 22nd week of 2010.

The longer answer is that Rheem has used a variety of serial number styles since the 1970’s. Style # 1 below is the most common style and often includes the actual manufacture date on the rating plate. These serial numbers can be found on all of Rheem  HVAC equipment including furnaces, boilers, air conditioning units, and on Rheem water heaters.

Reminder – these aren’t model numbers: This post is about Rheem serial numbers, not Rheem model numbers that have nomenclature related to series, capacity, and performance of Rheem HVAC equipment.

How to Read a Rheem Serial Number

Rheem uses a variety of styles of serial numbers. Following are 7 styles of serial numbers used by Rheem with explanations of the nomenclature and how to decode the manufacture date.

Style #1: 10 Characters – A Letter and 9 Numbers

In Style # 1 the serial number will begin with a letter followed by 9 more numbers. The date is coded in the first 4 numbers after the letter.

Example Serial #:  W421724596

Week/Month: The first 2 numbers are 42 meaning the 42nd week of the year which falls in October.

Year: The 3rd and 4th numbers indicate the year, so here they are 17, which means 2017.

Manufacture Date: October 2017

Style #2: 17 Characters – Letters & Numbers

Style # 2 is used on Rheem’s trademarked brands of heat controllers. The manufacture date is coded in the 9th through 12th characters which are all numbers. These 4 numbers will follow one of these letters – F,M, G, or N which identify the factory location.

Example Serial #:  AB7E203M129703576

Month: The 9th and 10th characters are the numbers 12 and indicate the 12th week of the year which is in March.

Year: The 11th and 12th characters are 97 and represent the year the unit was made. Here the numbers are 97, so 1997.

Manufacture Date: March 1997

Style #3: 14 Characters – Letters & Numbers

This style begins with 4 letters followed by a space and then a letter, either an F, M, G, or N, which indicates the plant where the unit was made. The letter is followed by 4 numbers which represent the manufacture date. The last 4 numbers are the manufacturing sequence.

Example Serial #:  8231  G0304  17845

Month: The 1st and 2nd numbers after the letter G are 03 and mean the unit was made in the 3rd week of the year, which is January.

Year:  The 3rd and 4th numbers, after the letter G,  are 04 and represent the manufacture year which is 2004.

Manufacturer Date: January 2004

Style #4: 15 Characters – Letters & Numbers

In this style, the date code is located in the middle of the serial number. The number will start with 2 letters and 3 numbers followed by a space. The first letter after the space refers to the factory. The next 4 numbers indicate the date and the last 5 numbers represent the manufacturing sequence.

Example Serial #:  BL259  M2215  00247

Month: The 1st and 2nd numbers after the space and just after the letter M are 22 and indicate the 22nd week of the year which falls in May.

Year: The next 2 numbers are 15 meaning the unit was made in 2015.

Manufacture Date: May 2015

Style #5: 1 Characters – Letters & Numbers

This style of serial numbers is commonly found on older forced air furnaces and Rheem water heaters.

The manufacture date is found in the first 4 characters, which are numbers.

Example Serial #:  0902C11246

Month: The first 2 numbers are 09 indicating the unit was made in September.

Year: The second set of numbers indicates the year, so here the numbers are 02 meaning the manufacture year is 2002.

Manufacture Date: September 2002

Style #6: 9 Characters – All Numbers

Style # 6 can be found on older Rheem water heaters and HVAC units made in the 1970’s and earlier. Most of these units are likely out of service now.

The date is coded in the last 4 characters of the serial number.

Example Serial #:  168252873

Month: The 6th and 7th characters are numbers and indicate the week the unit was made, so here the numbers are 28, meaning the 28th week of the year which is July.

Year: The last two numbers are 73 meaning the unit was made in 1973.

Manufacture Date: July 1973

Style #7: 14 Characters – 1 Letter & 13 Numbers

This style is similar to style # 3 but does not include any spaces within the number. In style # 7, the first 4 characters will be numbers followed by a letter. The four numbers following the letter are the date code.

Example Serial #:  7143W1519143722

Month: The 1st and 2nd number following the only letter are 15 and mean the 15th week of the year which falls into April.

Year: The 3rd and 4th numbers following the letter are 19 and indicate the unit was made in 2019.

On these units, you’ll also often find the manufacture date printed on the rating plate like this:  MFD/FAB   04/2019

Manufacture Date: April 2019

Where is the Rheem Serial Number?

The serial number for a Rheem indoor unit, like a furnace or air handler can be for on the rating or data plate or tag inside the front top cover.

The Rheem serial numbers for outdoor units like air conditioners and heat pumps can be found on the rating plate on the exterior back side of the unit.

Rheem Air Conditioners Age Lookup

If you want to look up the age of an air conditioning unit and can’t find the serial number in the above styles, you can enter it into the search bar at the Rheem website lookup page.

Written by

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree from Lone Star College and EPA & R-410A Certifications.

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