How old is my Dunkirk boiler?

Serial number age decoder for Dunkirk boilers: 3 format eras, the decode rule in plain English, transcribed tables, and the official lookup.

• Dunkirk boiler serial numbers in the 2005 to present format encode the year as digits 3-4 (20YY) and the WEEK = digits 1-2 (source: building-center.org).
• Example: serial 160500150 decodes to week 16 of 2005.
• Dunkirk boiler serial numbers in the 1979 to 2001 format encode the year as letter 2 (table below) and the month as letter 1: A Jan B Feb C Mar D Apr E May F Jun G Jul H Aug K Sep L Oct M Nov N Dec (I and J unused) (source: building-center.org).
• Example: serial HT11826 decodes to August 1996.
• Dunkirk's official lookup at dunkirk.com returns warranty / registration lookup.

Format eras

• 2005 to present VERIFIED
  #########digits 3-4 (20YY)
• 2003 to present VERIFIED
  AAA#####letters 1+3 combined: U_A=2003 U_B=2004 U_C=2005 U_D=2006 U_E=2007 U_F=2008 U_G=2009 U_H=2
• 1979 to 2001 VERIFIED
  AA#####letter 2: I=1979 J=1980 K=1981 L=1982 M=1983 A=1984 B=1985 C=1986 D=1987 E=1988 F=1989 G=1

How to read the serial

2005 to present formatVERIFIED

Shape ######### · example 160500150 · confidence high

Year

digits 3-4 (20YY)

Week or month

WEEK = digits 1-2

Example: serial 160500150 decodes to week 16 of 2005.

Listed under Utica in the source; Dunkirk is named in that format's family and the corporate link is an estimate, not a checked fact.

2003 to present formatVERIFIED

Shape AAA##### · example UBC14945 · confidence high

Year

letters 1+3 combined: U_A=2003 U_B=2004 U_C=2005 U_D=2006 U_E=2007 U_F=2008 U_G=2009 U_H=2010 U_I=2011 U_J=2012

Week or month

month = letter 2 (A=Jan..L=Dec, I=Sep)

Listed under Utica in the source; Dunkirk is named in that format's family and the corporate link is an estimate, not a checked fact.

1979 to 2001 formatVERIFIED

Shape AA##### · example HT11826 · confidence high

Year

letter 2: I=1979 J=1980 K=1981 L=1982 M=1983 A=1984 B=1985 C=1986 D=1987 E=1988 F=1989 G=1990 H=1991 N=1992 P=1993 R=1994 S=1995 T=1996 U=1997 V=1998 W=1999 9=Jan-Aug 2000 X=Sep-Dec 2000 Y=2001

Week or month

month = letter 1: A Jan B Feb C Mar D Apr E May F Jun G Jul H Aug K Sep L Oct M Nov N Dec (I and J unused)

Example: serial HT11826 decodes to August 1996.

Listed under Utica in the source; Dunkirk is named in that format's family and the corporate link is an estimate, not a checked fact.

Where the data plate is on a boiler

On the jacket: a plate or sticker on the front or side of the boiler casing, sometimes behind a removable front panel next to the gas valve or control.

General guidance, not brand-specific: the owner's manual or the installer can point to the exact spot. See the data plate guide.

For scale only: the InterNACHI Standard Estimated Life Expectancy Chart for Homes lists Boiler at 40 years of expected service (nachi.org). That chart is a guideline, not a prediction for your unit.

What we could not confirm

• Dunkirk is treated as sharing Utica's format because the source lists it in that family; the corporate relationship itself is an estimate.
• The 2003 to present format is documented but not decodable here: year position not parseable from prose: 'letters 1+3 combined: U_A=2003 U_B=2004 U_C=2005 U_D=2006 U_E=2007 U_F=2008 U_G='.
• Single 9-character style 160500150: week = digits 1-2, year = digits 3-4 (= Utica style 1).

Sources

• https://www.building-center.org/utica-hvac-age/
• https://www.building-center.org/dunkirk-hvac-age/
• img: Style-1_Dunkirk-Date-of-Manufacture_Serial-Number-Nomenclature.png
• img: Style-2_Utica_-Date-of-Manufacture_Serial-Number-Nomenclature.png
• img: Style-3_Utica + Style-3-Year-Chart_Utica
• https://dunkirk.com/owner-resources/warranty/official

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