Dating Residential Boilers
The following are brands of boilers commonly found in southeast Michigan. This list is not all encompassing, and mistakes are bound to happen. A contentious effort was made to provide the correct information to assist in determining the age of the boiler, but due to the numerous manufactures and the variations of dating codes, no liability can be assumed.
Bryant
For Bryant boiler manufactured form 1985 to the present, the date code is embedded in the first four placeholders of the serial number. Either the first four digits in the serial number is the week and year (WWYY), or the first two four digits are the year and month (YYMM).
Bryant boilers manufactured from 1980 to 1984, an 8-digit serial number was used with the first letter signifying the month (M=January…Z=December) and the numeral in the second position (1 through 4) represents the year.
Bryant boilers manufactured from 1970 to 1979, a 7-digit serial number was used. The first letter of the serial number signifies the month (A=January…L=December), and the second placeholder is a number signifying the year. (0=1970, 9=1979).
Burnham
Newer Burnham boilers have the date of manufacture listed in the upper right-hand corner of the data sticker. Older Burnham boilers have a Byzantine age code. Look for the ANSI date and add several year to get a rough approximation of the age, or contact the manufacturer.
Dunkirk
Dunkirk uses the first two digits of the serial number for the week, and the next two digits for the year. (WWYY)
Lochinvar
1979 through 2011
Lochinvar boilers manufactured in 1993 through 2011, the first placeholder in the serial number is the production year. (1993=K, 1994=L, 1995=M, 1996=N, 1997=p, 1998=S, 1999=T, 2000=W, 2001=X, 2002=Y, 2003=Z, 2004=A, 2005=B,2006=C, 2007=D, 2008=E, 2009=F, 2010=G, 2011=H, 2012=J.)
2012 through Present
For this period of time, Lochinvar uses the first two digits of the serial number for the year, and the next two digits for the week (YYWW).
Peerless
Between 1984 and 1999, the set of numbers after the dash were the month and year of manufacture (MMYY).
Beginning in 2000, the first set of numbers is the sequence number, the set of numbers after the dash is the year and month (-YYYYMM)
Teledyne Laars
The first digit or letter in the serial number represents the month, and the next two digits represent the production year (MYY).
Weil-McLain
Weil-McLain assigns a serial number to each boiler. The serial number prefix is “CP” followed by the actual serial number. The following chart can be used to date the boiler by the serial number:
| 1988 | 141001 | to 1681500 |
| 1989 | 1681501 | 1871500 |
| 1990 | 1871501 | 2056000 |
| 1991 | 2056001 | 2217391 |
| 1992 | 2217400 | 2399999 |
| 1993 | 2400000 | 2609500 |
| 1994 | 2609501 | 2815000 |
| 1995 | 2815001 | 3003000 |
| 1996 | 3003001 | 3213000 |
| 1997 | 3213001 | 3441400 |
| 1998 | 3441401 | 3621000 |
| 1999 | 3621001 | 3810000 |
| 2000 | 3810001 | 4055000 |
| 2001 | 4055001 | 4311000 |
| 2002 | 4311001 | 4586999 |
| 2003 | 4587000 | 4807000 |
| 2004 | 4807001 | 5047000 |
| 2005 | 5047001 | 5301000 |
| 2006 | 5301001 | 5454497 |
| 2007 | 5454498 | 5731063 |
| 2008 | 5731064 | 5957346 |
| 2009 | 5957347 | 6150483 |
| 2010 | 6150484 | 6368018 |
| 2011 | 6368019 | 6555277 |
| 2012 | 6555278 | 6779489 |
| 2013 | 6779490 | 6998292 |
| 2014 | 6998293 | 7209932 |
| 2015 | 7209933 | 7429423 |
| 2016 | 7429424 | An on, visit the www.weil.mclain.com/cp-lookup |
Utica
- Prior to 1979; the first two digits is the month, and the third and forth digits are the year. For example, 12-63 is interpreted as December of 1963.
- For years 1979 through 2002, the first letter in the serial number is the code for the month, and the second letter is the code for the year. See below.
- For years 2003 and after, all serial numbers begin with the letter “U”, the second letter is code for the month, and the third letter is code for the year.
A for January through L for December
| 9 Jan – Aug 2000 | |||
| J 1980 | G 1990 | X Sept – Dec 2000 | U_H 2010 |
| K 1981 | H 1991 | Y 2001 | U_I 2011 |
| L 1982 | N 1992 | Z 2002 | U_J 2012 |
| M 1983 | P 1993 | U_A 2003 | U_K 2013 |
| A 1984 | R 1994 | U_B 2004 | U_L 2014 |
| B 1985 | S 1995 | U_C 2005 | * See below |
| C 1986 | T 1996 | U_D 2006 | |
| D 1987 | U 1997 | U_E 2007 | |
| E 1988 | V 1998 | U_F 2008 | |
| F 1989 | W 1999 | U_G 2009 |
* 2015 and on, Utica now uses the first two digits of the serial number for the week, and the next two digits for the year.(WWYY)