How old is my furnace?

Different HVAC units come with different parts manufacturer’s warranty. Your home owner’s manual should indicate the warranty period. But how do you know how old your unit is?

Here is an explanation of how to read your furnace or HVAC serial number to determine the age of your equipment. 

Below is the unit serial number breakdown for Lifebreath, Keeprite, Carrier and Lennox HVAC equipment for Canada and USA.

LIFEBREATH

Example serial number styles/formats found:

• Style 1:  MPAA29100902341 (Pre 1995)

• Style 2:  000 051696000014209 (Post 1995)

• Style 3: MBAH 0920110887 (Post 1995)

STYLE 1: MPAA29100902341

Description: Fifteen (15) character Serial number begins with four (4) letter digits followed by eleven (11) numerical digits.

Year of manufacture can be determined by using the combined 5th & 6th numerical digits and reversing the order.  NOTE:  From 95-98 they used both a year reversal and non-reversed.  (i.e. "59"(reversed) or "95" (non-reversed) both indicated the manufacture year of 1995).

STYLE 2: 000 051696000014209

Description: Eighteen (18) digit numeriacal Serial number.

Month of manufacture can be determined by using the combined 4th & 5th numerical digits

Day of Month of manufacture can be determined using the combined 6th & 7th digits.

Year of manufacture can be determined using the combined 8th & 9th digits

STYLE 3: MBAH0920110887

Description: Serial number begins with four (4) letter digits followed by varied amount of numerical digits.

The month, day and year of manufacture can be determined by using the first six numerical digits

KEEPRITE

• Style 1:    G051650885

• Style 2:    L920671787

• Style 3: 9414B39332

• Style 4: 30512345

• Style 5: Z3Z xxxxx

Style 1:   G051650885

Year of manufacture can be determined by using the2nd & 3rd numerical digits.

Week of manufacture can be determined by using the 4th & 5th numerical digits

Style 2:   L920671787 with MFG. DATE 2/92

This serial # is identical to Style 1 (above), but the date of manufacture is simplified with the inclusion of a MFG Date clearly printed on the data tag.

Year of manufacture can be determined by using the2nd & 3rd numerical digits.

Week of manufacture can be determined by using the 4th & 5th numerical digits

Style 3:   9414B39332

Year of manufacture can be determined by using the1st & 2nd numerical digits.

Week of manufacture can be determined by using the 3rd & 4th numerical digits

Style 4:   30512345

Year of manufacture can be determined by using the1st numerical digit.  (See chart below)

Week of manufacture can be determined by using the 2nd & 3rd numerical digits

NUMBER	YEARS		NUMBER	YEARS
0	1980 or 1990		5	1985
1	1981 or 1991		6	1986
2	1982 or 1992		7	1987
3	1983 or 1993		8	1988
4	1984		9	1989

Style 5:   Z3Zxxxxx

Year of manufacture can be determined by using the 3rd letter digit.  (See chart below).

LETTER	YEAR		LETTER	YEAR
A	1978		O	1991
B	1979		P	1992
C	1980		Q	1993
D	1981		R	1994
E	1982		S	1970
F	1983		T	1971
G	1984		U	1972
H	1985		V	1973
J	1986		W	1974
K	1987		X	1975
L	1988		Y	1976
M	1989		Z	1977
N	1990

LENNOX

• Style 1:    1606B13871 -or- 5899L17212 (1973 and after)

• Style 2:     724 -or- 6512  (prior to 1973)

Style 1:    1606B13871 -or- 5899L17212 (Style used 1973 and after)

The first two digits of the serial number are the Factory or Plant Code.

Year of manufacture can be determined by using the 3rd & 4th positions of the serial number

Month of manufacture can be determined by using the 5th position (letter) of the serial number

Style 2:    724 -or- 6512 (Style used prior to 1973)

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

Month of manufacture can be determined by using the 3rd -or- 3rd & 4th position(s) of the serial number (months 1 through 12)

CARRIER

The date of production/manufacture or age of Carrier® brand HVAC equipment can be determined from the ten character serial number located on the rating data plate.

Example serial number styles/formats found:

• Style 1:     4006A17330

• Style 2:     850304091

• Style 3:     W4D14008 (U.S.) ~or~  4WD14008 (Canada)

• Style 4:     A167890

• Style 5:     6###### (U.S.) ~or~ 6#### (Canada)

• Style 6:    46U152456 or 2W13270  (one or two digits followed by a letter) Bryant & Carrier

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

Style 1:    4006A17330 (Since 1980)

This is the newest style for Carrier brand (or subsidiary) systems, and the age can be determined by the first four numbers.

The serial number style has been used since 1980, and is formatted by 4 numbers, a letter, then 5 numbers. A manufacture date is also often (but not always) included near the bottom of the data/rating tag or directly below the serial number.

CAUTION: This style can easily be confused with Lennox serial number styles, which could potentially lead to an incorrect manufacture date.

Year of manufacture can be determined by using the 3rd & 4th positions of the serial number

Week of manufacture can be determined by using the 1st & 2nd positions of the serial number

Style 2:    850304091 (During the 1980’s)

This is a Bryant or BDP brand style number (merged with Carrier in 1955 and BDP created in 1974). The age can be determined by the first four numbers.

The serial number style was used primarily during the 1980's, and is formatted by a 9 character, all numerical serial number.

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

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

Style 3:    W4D14008 (U.S.) ~or~  4WD14008 (Canada)

The serial number style was used exclusively from 1980-1984 and ONLY used letters M through Z to represent the month.

CAUTION: Canada units reverse the Year and Month positions from U.S. made serial number styles.

Description:

U.S. Systems: Eight (8) character serial number beginning with letters from M to Z.  Formatted by one (1) letter (M-Z) followed by one (1) numerical digit and then ends with six (6) more characters (all numerical digits, or letter and digits).

Year of manufacture can be determined by using the 2nd position of the serial number (See chart below)

Month of manufacture can be determined by using the 1st position of the serial number (See chart below)

Canadian Systems: Eight (8) character serial number beginning with a numerical digit, then letter from M to Z.  Formatted by one (1) numerical digit, followed by one (1) letter (M-Z) and then ends with six (6) more characters (all numerical digits, or letter and digits).

Year of manufacture can be determined by using the 1st position of the serial number (See chart below)

Month of manufacture can be determined by using the 2nd position of the serial number (See chart below)

LETTER	MONTH		LETTER	MONTH
M	JANUARY		T	JULY
N	FEBRUARY		V	AUGUST
P	MARCH		W	SEPTEMBER
Q	APRIL		X	OCTOBER
R	MAY		Y	NOVEMBER
S	JUNE		Z	DECEMBER

Style 4:    A167890

The serial number style was used exclusively from January 1, 1969 to December 31, 1979.

Description: Seven (7) character serial number started with letters from A to L.  Formatted by one (1) letter (A-L) followed by one (1) numerical digit (using 0-9) and then ends with five (5) numerical digits.

Year of manufacture can be determined by using the 2nd position of the serial number (See chart below)

Month of manufacture can be determined by using the 1st position of the serial number (See chart below)

LETTER	MONTH		LETTER	MONTH
A	JANUARY		G	JULY
B	FEBRUARY		H	AUGUST
C	MARCH		I	SEPTEMBER
D	APRIL		J	OCTOBER
E	MAY		K	NOVEMBER
F	JUNE		L	DECEMBER

Style 5:    6###### (U.S.) ~or~   6#### (Canada) - PRIOR to 1969

Description:

U.S. Only: Seven (7) character all numeric serial number.

Canada Only: Five (5) character all numeric serial number.

Year of manufacture can be determined by using the 1st position of the serial number.

Style 6:    46U152456 or 2W13270  (one or two digits followed by a letter) Bryant & Carrier

Description:  Seven (7) to nine (9) character serial number - always beginning with a 1 or 2 digit number followed by a letter. This style was used from 1960 to 1979.

Year of manufacture can be determined by using the 1st letter (2nd or 3rd position) of the serial number: beginning with L and cycling through to end with H (skipping letters O, Q, and Z) representing 1960 - 1979 - See Chart

Week of manufacture can be determined by using the 1st -or- 1st & 2nd positions (number/s) of the serial number: 1-52 representing weeks of the year

Letter  -  YEAR

• L  -  1960

• M  -  1961

• N  -  1962

• P  -  1963

• R  -  1964

• S - 1965

• T - 1966

• U - 1967

• V - 1968

• W - 1969

• X  -  1970

• Y  -  1971

• A  -  1972

• B  -  1973

• C  -  1974

• D - 1975

• E - 1976

• F - 1977

• G - 1978

• H - 1979