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ICP family

How old is my Heil furnace?

Enter the serial number from the label. The date comes from Heil's documented serial rules, not a guess.

Look for “Serial No.” or “S/N” on the label. Spaces and dashes are fine.

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How to read a Heil furnace serial number

Heil is one of the brands International Comfort Products (ICP) names in its own furnace warranty, and Heil equipment uses the ICP serial layout: a plant letter, two digits for the year, two for the week, then a sequence number. We decode that layout from 1988 on, for Heil furnaces, air conditioners, heat pumps, air handlers and packaged units. Older Heil serials in other styles aren’t decoded.

  • Plant letter + year + week (1988 onward)

    Example: L943321238 (Heil) was made in August 1994. ICP serials (Heil, Tempstar, Comfortmaker, Arcoaire and others) start with a plant letter ("L"), then two digits for the year (1994) and two for the week (33).

Not decoded yet: Serials shaped like 4 digits + letter + 5 digits are not decoded: sources disagree on whether the year or week comes first. 1970s–80s letter formats are also not decoded.

Where to find the serial number

Turn the furnace off at its switch, then remove the upper access door (the burner or blower compartment). The rating plate is on the inside wall of the cabinet or on the back of the door.

The plate lists the model number and serial number; many newer plates also print a date of manufacture.

Heil furnace model numbers

If the brand name isn't visible on the label, the model number can help. Model numbers like these follow the Heil / Tempstar / Comfortmaker / Arcoaire / KeepRite / AirQuest / International Comfort Products nomenclature:

How long does a furnace last?

A typical furnace lasts about 15–20 years. That's a general estimate: maintenance, usage, climate and installation all matter, and age alone doesn't tell you a unit's condition.

Range from NAHB / Bank of America, Study of Life Expectancy of Home Components (2007, archived copy), Carrier: how long does a furnace last? and Lennox: how long does a furnace last?.

Heil furnace recalls

From the U.S. Consumer Product Safety Commission, checked 2026-09-29. A decoded result checks your model number against recalls live.

Questions

My Heil serial starts with an H and has only nine characters. Can you date it?
Not yet. Industry references describe an older Heil style that starts with a decade letter, with H standing for the 1980s, but only the H is backed by sources that agree; the other decade letters come from a single source. Rather than guess, we leave these serials undecoded; if the plate prints a manufacture date, use that.
Does a model number starting with H mean the unit is a Heil?
Not on its own. ICP’s brand sites list the same H5H8T outdoor unit under Heil, Arcoaire and AirQuest, and G-series furnaces under Heil, Comfortmaker, KeepRite, AirQuest and Day & Night. Check the brand name on the cabinet; the serial rule is the same for all of these brands.
How can I tell how old my Heil furnace is?
Find the serial number on the rating plate and enter it above. Heil furnaces use the ICP family serial format, which includes the manufacture date. For example, L943321238 was made in August 1994: ICP serials (Heil, Tempstar, Comfortmaker, Arcoaire and others) start with a plant letter ("L"), then two digits for the year (1994) and two for the week (33).
Where is the serial number on a Heil furnace?
Turn the furnace off at its switch, then remove the upper access door (the burner or blower compartment). The rating plate is on the inside wall of the cabinet or on the back of the door. The plate lists the model number and serial number; many newer plates also print a date of manufacture.
How long does a furnace usually last?
A typical service life is about 15–20 years. That's a general estimate: maintenance, usage, climate and installation all matter, and age alone doesn't tell you a unit's condition.
Do Tempstar, Comfortmaker, Arcoaire, KeepRite, AirQuest and International Comfort Products furnaces use the same serial format?
Yes. Heil, Tempstar, Comfortmaker, Arcoaire, KeepRite, AirQuest and International Comfort Products use the same serial-number conventions (ICP family), so the same decoding rules apply.
How reliable is the result?
The ICP family rules come from documented sources, but they're in Beta while we check more real-world examples, so results are capped at medium confidence. If a serial doesn't match a documented format, we say so instead of guessing.

Same serial format: Tempstar furnace, Comfortmaker furnace, Arcoaire furnace, KeepRite furnace, AirQuest furnace, International Comfort Products furnace

Other Heil equipment: air conditioner, heat pump

Sources

Rules last reviewed 2026-09-28. These rules are in Beta while we verify more real-world examples, so results are capped at medium confidence.

Manufacture dates are decoded from manufacturer serial-number conventions and available documentation. Serial formats can change. Verify critical equipment information with the manufacturer when necessary.