Tempstar, Comfortmaker, Arcoaire & Day & Night Age
Tempstar, Comfortmaker, Arcoaire and Day & Night are all built by ICP and share one serial code. A plant letter is followed by the two-digit year and the two-digit week. Pick your brand and enter the serial.
Part of the hvac age lookup
Serial number age lookup
One factory, four nameplates
International Comfort Products (ICP), based in Lewisburg, Tennessee, makes residential heating and cooling equipment under several brands. Each is sold through a different network of distributors and contractors:
| Brand | What you’ll typically see |
|---|---|
| Tempstar | Widely installed by independent contractors. Many models have a Tempstar-specific trim and badge. |
| Comfortmaker | Long-running brand, often marketed on quiet operation (its SoftSound line). |
| Arcoaire | Smaller brand with its own distributor network, especially in parts of the South and Midwest. |
| Day & Night | One of the oldest names in the group, popular in the West. |
Heil is ICP’s other major US brand and has its own page. In Canada, ICP equipment is also sold as KeepRite.
These brands are grouped on one page because they share everything that matters for dating: the same serial format, the same plants and, for a given tier, nearly the same equipment. Each brand’s history and dealer network differ, but the decoding doesn’t.
Where to find the serial number
- Outdoor unit: on the rating plate on the side of the cabinet, near the electrical access.
- Furnace: inside the blower compartment door.
- Coil or air handler: on the cabinet.
The serial is usually one letter followed by nine digits.
How the ICP date code works
| Part | Example (W061812345) | Meaning |
|---|---|---|
| Letter | W | Plant |
| 2 digits | 06 | Year (2006) |
| 2 digits | 18 | Week (early May) |
| rest | 12345 | Sequence |
- Year
- Week
- Not part of the date
Worked examples
| Serial | Built |
|---|---|
| W061812345 | May 2006 (week 18) |
| E142312345 | June 2014 (week 23) |
| L943312345 | August 1994 (week 33) |
| A210712345 | February 2021 (week 7) |
Example serials are made up to show the format; they don't belong to real units.
Choose your exact brand in the tool’s menu (Tempstar, Comfortmaker, Arcoaire or Day & Night). The result is the same, but it keeps your report accurate if anything looks off.
A note on counting positions
Some guides say “positions 2 and 3 are the year”. They count the letter as position 1. Others say “the first two digits are the year”, counting digits only. Both describe the same thing: the two digits straight after the letter.
How long ICP equipment lasts
| Equipment | Typical life |
|---|---|
| Central air conditioner | 12–17 years |
| Heat pump | 10–15 years |
| Gas furnace | 15–20 years |
ICP’s products are mainstream, mid-priced equipment. Like any brand, they reach the upper end of these ranges when they’re correctly sized, charged and maintained, and fall short when they aren’t.
What to do with your result
Under 10 years: look for the registration certificate. ICP brands generally offer longer parts coverage on registered equipment.
10 to 15 years: keep servicing it. Routine electrical parts are worth replacing; get a replacement quote before any compressor or heat-exchanger work.
Over 15 years: plan a replacement. Parts for the four brands are often interchangeable, which can help keep an older system running while you shop.
Frequently asked questions
How do I read a Tempstar serial number?
Skip the first letter. The next two digits are the year and the following two are the week. W061812345 was built in week 18 of 2006, early May.
Are Tempstar, Comfortmaker, Arcoaire and Day & Night the same?
They're built by the same company (International Comfort Products, part of Carrier), in the same plant and largely from the same designs. The main differences are the badge, the cabinet details and which distributors sell them.
Does a Comfortmaker serial work the same as Heil?
Yes. All ICP brands use the same plant letter, year and week layout.
Which ICP brand is best?
For the same model tier they're essentially equivalent. Choose based on the installing contractor, the warranty terms offered and local parts availability rather than the name.
Sources and accuracy
The ICP: Heil / Tempstar / Comfortmaker / Arcoaire / Day & Night decoder is built from these references and cross-checked between them. Facts are restated in our own words; any mistakes are ours.
Status: being verified against real data plates. Rules last reviewed 2026-10-18; page updated 2026-11-06. Not affiliated with ICP: Heil / Tempstar / Comfortmaker / Arcoaire / Day & Night. Report a wrong result.
Part of the hvac age lookup
This page covers one brand. For all furnace, air conditioner and heat pump brands, go to the hvac age lookup.