Home / Brands / Intertherm / Central Air Conditioner

How old is my Intertherm air conditioner?

Serial number age decoder for Intertherm central air conditioners: 3 format eras, the decode rule in plain English, transcribed tables, and the official lookup.

Serial number decoder for Intertherm air conditioner

Serial no.

Type the serial from the data plate, not the model number. Nothing is sent anywhere; the tables are in this page.

Format example: GBB030708229

Intertherm air conditioner serial numbers in the era not stated format encode the year as digits 4-5 of the serial, i.e. the first two numerals after the 3-letter prefix (03 = 2003) and the month as digits 6-7 (07 = July) (source: building-center.org).
Example: serial GBB030708229 decodes to July 2003.
Intertherm air conditioner serial numbers in the era not stated format encode the year as digits 3-4 after the middle factory letter (91 = 1991) and the week as digits 1-2 after the middle factory letter (38) (source: building-center.org).
Example: serial MN3D102 F3891 4228 decodes to week 38 of 1991.
Intertherm air conditioner serial numbers in the era not stated format encode the year as digits 4-5 (99 = 1999) and the month as digits 6-7 (05 = May) (source: building-center.org).
Example: serial G6R9905-05028 decodes to May 1999.
Intertherm's official lookup at intertherm.com returns warranty / registration lookup.

Format eras

era not stated VERIFIED
AAA#########digits 4-5 of the serial, i.e. the first two numerals after the 3-letter prefix (03 = 2003
era not stated VERIFIED
AA#A### A#### ####digits 3-4 after the middle factory letter (91 = 1991)
era not stated VERIFIED
A#A####-#####digits 4-5 (99 = 1999)

How to read the serial

era not stated formatVERIFIED

Shape AAA######### · example GBB030708229 · confidence high

Year: digits 4-5 of the serial, i.e. the first two numerals after the 3-letter prefix (03 = 2003)
Week or month: month = digits 6-7 (07 = July)
Plant: none; the 3-letter prefix is a model-series code ("can be any combination of letter and number sequence, typically like model number"), not a plant

Example: serial GBB030708229 decodes to July 2003.

Trap: Nortek/Nordyne family ROOT style 1: 12 chars = 3 letters + YYMM + 5-digit sequence; may carry hyphens after position 3 and/or 7 (GBB-030708229, GBB-0307-08229). Used by every Nortek brand page: Intertherm/Kelvinator/Maytag/Frigidaire/Tappan/Westinghouse/Philco (FGA030310579 = March 2003), Gibson (JSA060103994 = Jan 2006), Broan (GT3050153269 = Jan 2005 - note Broan's prefix has a digit, so allow [A-Z0-9]{3} if strict matching fails). Century: 20YY for this style. Applies to: Nordyne | Intertherm | Miller | Frigidaire HVAC | Maytag HVAC | Tappan HVAC | Westinghouse HVAC | Kelvinator HVAC | Philco HVAC | Gibson HVAC | Broan HVAC

Listed under Nordyne in the source; Intertherm is named in that format's family.

era not stated formatVERIFIED

Shape AA#A### A#### #### · example MN3D102 F3891 4228 · confidence medium

Year: digits 3-4 after the middle factory letter (91 = 1991)
Week or month: week = digits 1-2 after the middle factory letter (38)
Plant: middle letter = factory code (F in the example; Rheem uses F, M, G, W, N)

Example: serial MN3D102 F3891 4228 decodes to week 38 of 1991.

Trap: Nortek family ROOT style 2 = Rheem-style serial; building-center: 'This style is like Rheem serial numbers, and likely indicates Rheem manufactured the unit for Nordyne.' Tappan/Westinghouse/Philco pages list it as 'F3891 4228' (9 chars, year = digits 3-4 after the letter). Same regex as the Rheem 3-block rule in formats.json.

Listed under Nordyne in the source; Intertherm is named in that format's family.

era not stated formatVERIFIED

Shape A#A####-##### · example G6R9905-05028 · confidence high

Year: digits 4-5 (99 = 1999)
Week or month: month = digits 6-7 (05 = May)
Plant: letters 1 and 3 + digit 2 = unexplained prefix (no table)

Example: serial G6R9905-05028 decodes to May 1999.

Trap: Nortek family style 'G#R YYMM-#####' (12 chars + dash). Not on the Nordyne root page but on every sub-brand page (Intertherm, Kelvinator, Maytag, Broan, Frigidaire, Tappan, Westinghouse, Philco) and the ONLY style on the Miller page (G5R9510-01034 = Oct 1995). Century: 19YY for 9x, 20YY for 0x - by context.

Listed under Nordyne in the source; Intertherm is named in that format's family.

Where the data plate is on an air conditioner

On the outdoor condenser: a metal or foil plate on the side or back of the cabinet, often near the refrigerant line connections. Some brands repeat it inside the electrical access panel.

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 Air Conditioner (central) at 7 to 15 years of expected service (nachi.org). That chart is a guideline, not a prediction for your unit.

Official lookup: the authority

Open the official Intertherm lookup takes serial number; returns warranty / registration lookup; URL verified live

This site is a reference built from published tables. The manufacturer's own lookup wins whenever the two disagree.

What we could not confirm

Styles: FGA030310579 (root style 1) and G6R9905-05028 (family style 3). intertherm.com curl 200 but JS-rendered (no text); it is a brand site, not a serial lookup. Water-heater page https://www.building-center.org/intertherm-water-heater-age/ not fetched.

Sources

https://www.building-center.org/nordyne-hvac-age/
img: Nordyne-style-1-2023.jpg (transcribed)
https://www.building-center.org/intertherm-hvac-age/
https://www.building-center.org/gibson-hvac-age/
https://www.building-center.org/broan-hvac-age/
img: Nordyne-style-2-2023.jpg (transcribed)
https://www.building-center.org/tappan-hvac-age/
https://www.building-center.org/westinghouse-hvac-age/
https://www.building-center.org/miller-hvac-age/
https://www.building-center.org/kelvinator-hvac-age/
https://www.building-center.org/maytag-hvac-age/
https://www.intertherm.com/official