Dating Furnace & Water Heaters

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)

The following are brands of furnace and central air conditioners commonly found in southeast Michigan. This list is not an all encompassing list, however, a contentious effort was made to provide the correct information to assist in determining the age of the HVAC (Heating, Ventilation, and Air Conditioning) equipment despite the numerous manufactures and the variations of dating codes.

First, when dating an HVAC unit, first look at the data tag, the manufacturing date may be displayed on the data sticker.

Second, look for the serial number. Sometimes the date is hidden within the serial number. For example, C12 could indicate that the water heater was constructed in March of 2012. Also look at the serial number. If there are 4 numerals at the start of the serial number, the first two numbers could represent the year, the next two numerals could represent the month or the week of manufacture, or vice versa. Compare this information to the “ANSI” (American National Standards Institute) or “CSA” (Canadian Standards Association) code dates described in the following paragraph.

Third, if the date of manufacture is not immediately evident a little sleuthing around the label may reveal the date of manufacture. Look at the lower portions of the data sticker for the letters “ANSI” or “CSA”. The four digits after the referenced standard authority usually represent the code or standards to which the furnace or air conditioner was constructed. For example, the if the “ANSI” or “CSA” year is 2006, the unit was likely constructed during a three, possibly six year window from 2007 through 2012.

Finally, if all else fails look for the brand and the serial number in the following paragraphs:

Amana (A member of the Goodman and Janitrol family of furnaces.)

For units manufactured since the early 1990’s, the first two placeholders in the serial number indicate the year (“Y”), and the next two numbers indicate the week (“W”) of manufacture (YYWW).

American Standard (Trane and Unitary)

Newer American Standard products have the month and year of manufacture on the date sticker. If the date is not readable or present on the data sticker, American Standard uses several dating codes in their serial numbers. The first code format would is the production year is the first numeral in the serial number followed by the week (YWW). A second code format is the first placeholder in the serial number is a letter representing the month followed by two digits for the year (MYY). An older code format is the first two digits of the serial number represent the year, and the next two digits represent the month (YYMM)

Arcoaire

See “International Comfort Products”

Armstrong

Armstrong uses three methods of imbedding the date codes in the serial numbers. With the first method, the first two numerals of the serial number represent the year, and the next two numerals represent the week (YYWW). The second method uses the first two digits of the serial number represent the week, and the third and forth numbers represent the year of manufacture (WWYY). The third method uses the third and fourth placeholders of the serial number are numerals that represent the year of manufacture. The letter after the year is a letter that represents the month (**YYM).

Bryant (Carrier, Payne)

For Bryant, Payne, and Carrier HVAC products manufactured form 1985 to the present, the date code is embedded in the first four placeholders of the serial number. The first two numerals in the serial number is the week of manufacturer (01 to 52 weeks in the year), and the third and fourth digits are the year. For example, the date code in this serial number “2901A18288” is the 29th. week of 2001.

Carrier (See “Bryant”)

Coleman (see York)

Comfortmaker

See “International Comfort Products”

Ducane (Also see Lennox)

Ducane uses several serial number date codes. For example, the third and forth placeholders in the serial number is the production year followed by a letter for the month (**YYM). Another variation of their code is the second and third placeholders are the year and the fourth and fifth placeholders are the week (*YYWW).

Evcon (see York)

Fraser-Johnson (see York)

General Electric

In general, all of the General Electric furnaces, central air conditioners, and central heat pumps were last manufactured in the mid 1980’s. These units are beyond the expected service life. Note that “Trane” acquired the HVAC product line from General Electric and that “American Standard” acquired “Trane”.

Gibson (see Nordine)

Goodman (Goodman brands include Amana, Janitrol)

For units manufactured since the early 1990’s, the first two placeholders in the serial number indicate the year, and the next two numbers indicate the week of manufacture (YYMM).

Heil

See “International Comfort Products”

International Comfort Products (This product family includes Arcoaire, Comfortmaker, Heil, Kenmore, Tempstar)

The first place holder in the serial number is a letter for the month followed by two numerals representing the year (MYY).

Another method of dating some International Comfort Products equipment is the serial number starts with an “L” followed by two numerals the represent the year (LYY).

Janitrol (A member of the Goodman family of furnaces.)

For units manufactured since the early 1990’s, the first two placeholders in the serial number indicate the year, and the next two numbers indicate the week of manufacture (YYMM).

Kenmore

See “International Comfort Products”

Lennox

After 1974, the numerals in the third and forth placeholder of the serial number (**YYM****)indicate the year, and the fifth placeholder is a letter the represents the month. The month codes are A=January, B=February, C=March, D=April, E=May, F=June, G=July, H=August, J=September, K=October, L=November, M=December. (“I” is omitted as it looks like the numeral “1”).

Luxaire (see York)

Magic Chef (1980 through 1998)

The date code for Magic Chef is in the third and second from last place holders in the serial number. The third from last letter is the month, and the second from last letter is the year. (****MY*)

The month codes are A=January, B=February, C=March, D=April, E=May, F=June, G=July, H=August, J=September, K=October, L=November, M=December. (“I” is omitted as it looks like the numeral “1”).

Nordine (Gibson)

Nordine uses several codes

1. The first method is the fourth and fifth placeholders in the serial number is the year, and the sixth and seventh place holders are the month (***YYMM).
2. The second method uses the numerals in the third and forth placeholders for the year (**YY).

Payne

See “Bryant”

Rheem and Ruud

In the middle of the serial number will the letter “F” or “M”, the following four numbers are the week and the year. (“F”WWYY) or (“M”WWYY)

Trane

See “American Standard”

York (In Michigan, the common members York family include: Coleman, Evcon, Frasier-Johnson, and Luxaire.)

The York family of HVAC equipment uses several date codes, some inherited by acquisitions of other brands. The following three formats can help date the majority of the HVAC units in the family:

The simplest format is first two numbers in the serial number are year, the next two numbers are the month (YYMM).

For 2005 and after, a ten-place serial number is used. The first place holder is a letter, the second place holder is a digit which represents the first number of the year manufactured, the third place holder is a letter followed by the fourth place holder being a digit that represents the second number of the year manufactured. For example, the serial number of “W1E3062387”, the date of manufacture was in “2013”.

For 2004 and previous years, the third placeholder in the serial number is a letter. This letter represents the year. Y=1990, Z=1991, A=1992, B=1993, C=1994, D=1995, E=1996, F=1997, G=1998, H=1999, J=2000, K=2001, L=2002, M=2003, N=2004.

The following list of brands are of water heaters commonly found in southeast Michigan. This list is not an all encompassing list, however, a contentious effort was made to provide the correct information to assist in determining the age of the water heater despite the numerous manufactures and the variations of dating codes.

First, when dating a water heater, first look at the data tag, the manufacturing date may be displayed on the data sticker.

Second, look for the serial number. Sometimes the date is hidden within the serial number. For example, C12 could indicate that the water heater was constructed in March of 2012. Also look at the serial number. If there are 4 numerals at the start of the serial number, the first two numbers could represent the year, the next two numerals could represent the month or the week of manufacture, or vice versa. Compare this information to the “ANSI” (American National Standards Institute) or “CSA” (Canadian Standards Association) code dates described in the following paragraph.

Third, if the date of manufacture is not immediately evident a little sleuthing around the label may reveal the date of manufacture. Look at the lower portions of the data sticker for the letters “ANSI” or “CSA”. The four digits after the referenced standard authority usually represent the code or standards to which the water heater was constructed. For example, the if the “ANSI-Z” year is 2006, the water heater was likely constructed during a six year window from 2007 through 2012.

Finally, if all else fails look for the brand and the serial number in the following paragraphs:

American (also Champion, Craftmaster, Ace, Tru-Test, Whirlpool, U.S.)

The first two digits in the serial number represent the year, the next two digits represent the week of manufacture. For example, “0732” indicated that the water heater was constructed in 2007 in the 32 week.

A. O. Smith

Prior to 2008, AO Smith used the second letter as the month code followed by 2-digits which represent the year. For example, F08 is the sixth month of 2008. (The letter “I” is skipped as it looks too much like a “1”.) After 2008, AO Smith used the first two digits in the serial number to represent the year followed by more numerals representing the week. For example, 0806 is the sixth week of 2008.

Bradford -White (also Lochinvar)

Year (first digit) Month (second digit)

A 1984		A 2004
B 1985		B 2005
C 1986		C 2006
D 1987		D 2007
E 1988		E 2008
F 1989		F 2009
G 1990	A January	G 2010
H 1991	B February	H 2011
J 1992	C March	J 2012
K 1993	D April	K 2013
L 1994	E May	L 2014
M 1995	F June	M 2015
N 1996	G July	N 2016
P 1997	H August	P 2017
S 1998	J September	S 2018
T 1999	K October	T 2019
W 2000	L November	W 2020
X 2001	M December
Y 2002
Z 2003

Due to a computer error, there were some 0A models manufactured=1997

Rheem (Lowe’s, Ruud)

Rheem uses a 2-digit month followed by a 2-digit year. For example, 0608 represents the sixth month followed by the year. Or June of 2008.

State (Ace, Barnett, Kenmore, Richmond)

Before 2008, State used a code having the first letter representing the month and the next two digits representing the year. For 2008 and after, use A. O. Smith’s code. State was acquired by AO Smith and uses Smith’s code. The first two digits in the serial number are the year followed by two more for the week. For example, 0806 is the sixth week of 2008.