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How old is my Tempstar furnace or AC?
Type the serial number from the Tempstar label to see when it was built. Tempstar units are built by ICP, a Carrier company, so the serials follow that company's format.
Example
- LPlant: L
- 90Year: 90 = 1990
- 37Week: 37 (around September)
Built Week 37 of 1990 (around September)
36 years, 1 month old
Past typical life. Past the usual 15 to 25 year lifespan. Watch for rising gas bills, uneven heat, a yellow or flickering burner flame, rust or soot, and a carbon monoxide alarm.
How this was read
- The first letter, L, is the plant that built it.
- The next two digits, 90, are the year: 1990.
- The two digits after that, 37, are the week of the year.
Format: ICP plant letter, year and week. Sources: CPSC 2005 ICP packaged unit recall (serial format L004112345), ICP serial number nomenclature (Tempstar parts), InspectAPedia: Tempstar age, Building Intelligence Center: Heil, Inspector Handbook: Heil.
Reading a Tempstar serial number
Tempstar is an ICP brand. The serial starts with a plant letter, then the year and the week. L9037 means the 37th week of 1990.
About Tempstar
- After Inter-City Gas bought Heil-Quaker from Whirlpool in 1986, it put the Tempstar name on products that had carried the Whirlpool name.
- In Canada in the late 1990s, Tempstar was sold through plumbing and heating wholesalers, while ICP’s other brands went through HVAC distributors.
- ICP still sells Tempstar today, alongside Heil, Comfortmaker, Arcoaire, Day & Night, KeepRite and Airquest.
Sources: Heil Manuals, parts lists, wiring diagrams for HVAC equipment (InspectAPedia), History of Whirlpool Corporation, International Comfort Products Corp Form 10-K405 for 1997, Our Brands (International Comfort Products)
ICP plant letter, year and week
Used about 1990 to today. Example: L004112345
Heil, Tempstar, Comfortmaker, Arcoaire, KeepRite and Day & Night serials start with a plant letter, then the year (2 digits), then the week (2 digits). L0041 means the 41st week of 2000. This is the reverse of Carrier’s week-then-year order.
Worked example: L903789847 was built Week 37 of 1990 (around September), so it is 36 years, 1 month old as of October 2026.
Sources: CPSC 2005 ICP packaged unit recall (serial format L004112345), ICP serial number nomenclature (Tempstar parts), InspectAPedia: Tempstar age, Building Intelligence Center: Heil, Inspector Handbook: Heil
Heil-Quaker 1980s year digit and week
Used 1980 to 1989. Example: H55116328
Heil-Quaker units from the 1980s have a shorter serial that starts with H. The digit after the H is the year in the 1980s, and the next two digits are the week. H5511 means the 51st week of 1985.
Worked example: H55116328 was built Week 51 of 1985 (around December), so it is 40 years, 10 months old as of October 2026.
Sources: CPSC 2005 ICP packaged unit recall (serial format L004112345), ICP serial number nomenclature (Tempstar parts), InspectAPedia: Tempstar age, Building Intelligence Center: Heil, Inspector Handbook: Heil
Tempstar recalls
Recalls from the U.S. Consumer Product Safety Commission that name Tempstar. Whether a unit is included depends on its model and build date; the checker above flags matches.
| Year | Recall | Hazard |
|---|---|---|
| 2005 | ICP gas-electric packaged units | The control board can catch fire. |
| 1996 | Ducane-built oil furnaces sold under many brands | The heat exchanger can crack. |