In this article, we’ll show you how to identify the age of your pool pump motor using its serial number. Knowing the age of your motor helps you decide if it is worth attempting a repair or replacing it with a new one.
Most of the pool industries’ whole pumps come with a Century motor, and they are also the top replacement motor choice. This guide is specific to Century motors.
Where to find the serial number?
The serial number is usually at the top corner of the motor’s label, as shown in the picture. Century has also provided a secondary serial tag. The secondary tag is a barcode with a list of numbers under it, confirming one of the below formats.
Century motors have used three serial number formats in the last ten years. We’ll break down the oldest first.
Pool Pump Serial Number – Old Format
The old century motor format consists of Serial Letter, Serial Number, and the Manufacture Sequence. You can see how these codes can be deciphered in the charts below. Unfortunately, this format was discontinued in the 2010s, but I cannot find the exact year.
| Serial Letter | Year | Serial Letter | Year | Serial Letter | Year |
|---|---|---|---|---|---|
| BB | 1984 | BL | 1993 | BX | 2002 |
| BC | 1985 | BM | 1994 | BY | 2003 |
| BD | 1986 | BN | 1995 | BZ | 2004 |
| BE | 1987 | BP | 1996 | CA | 2005 |
| BF | 1988 | BR | 1997 | CB | 2006 |
| BG | 1989 | BS | 1998 | CC | 2007 |
| BH | 1990 | BT | 1999 | CD | 2008 |
| BJ | 1991 | BU | 2000 | CE | 2009 |
| BK | 1992 | BW | 2001 | CF | 2010 |
| Serial Number Designation | Month | Serial Number Designation | Month |
|---|---|---|---|
| 1 | January | 7 | July |
| 2 | February | 8 | August |
| 3 | March | 9 | September |
| 4 | April | 10 | October |
| 5 | May | 11 | November |
| 6 | June | 12 | December |
New Format
Century motors use a five-digit code to denote manufactured date. The first three digits indicate the day of the year, and the next two digits note the year. For the longer format in this set, disregard the beginning letter; it’s not necessary to determine the date.
If you are like me and don’t have a calendar with numbered days for the last ten years, use this Calendar-365 tool to understand your serial number date.
Do you have any questions about your Century brand pool pump motor? If so, leave a comment down below. Thank you for reading.
Trying to find a replacement for a Century motor. I recently bought a house with a pool, so not sure which number is correct. I have a sticker on one side and the nameplate on the other
Sticker:
Serial #: 03951611301030
P/N: 355339S (MTR PKG SQFL 3/4 HPF 1 A)
Nameplate:
Motor #: 168452
Motor Package #: 355339S
230/115V
60 Hz 1PH
3450 RPM
Max Amps 7.1/14.2
Any suggestions on a good replacement?
Hello,
The correct motor replacement for your 168452 / 355339S motor is the Century (A.O. Smith) 1.0 HP Up Rate Motor, Square Flange 56Y Frame, Single Speed – Model B2853
Hello. Trying to identify how old my pump motor is but it doesn’t fall into the above categories. It is an AO Smith branded motor with a SER of 8L05.
That serial number does not match either of the formats shown in the article. Are you missing a letter or number?
Is this on a pool or spa pump?
He’s probably not missing a letter. My serial number doesn’t match the format in either document.
Is your pump motor on a pool and spa pump? Or is it a different style? A.O. Smith makes motors for a wide range of products, and those motor types may have different serial number formats.