How old is my KeepRite furnace or air conditioner?

By Dana Whitlock. Updated October 2026. Widely documented.

KeepRite serials can run eleven characters, one longer than you might expect. On units from the mid-1990s on, a letter comes first, then four digits that hold the date, year first and week second. The Energy Trust of Oregon's contractor reference shows R9435123455 as a 1994 unit.

KeepRite has a longer and messier serial history than its sister brands. Some older KeepRite and Inter-City plates use layouts this tool deliberately leaves alone, so check the pattern before you trust a result.

Where to find the label on a KeepRite furnace

KeepRite outdoor units carry the data plate on the cabinet exterior; on many models it sits near the electrical disconnect side. Furnaces keep it behind the blower door, on the door itself or the inner cabinet wall. Turn the furnace off before opening it and keep fingers out of the blower area. In basements, a headlamp leaves both hands free to hold the door and take a photo.

How to read the code

Modern KeepRite: letter, two-digit year, two-digit week, then the sequence. Note that the sequence can run to six digits, so a KeepRite serial may be eleven characters long instead of ten, as in the 1994 example above. Years 80 to 99 are 1900s years and 00 forward are 2000s years. If the serial has a letter in the first spot and then four digits that make sense as a year and week, the tool will read it.

Real serials in this code

When the format changed

KeepRite labels have changed more than once. The tool does not decode three older styles: serials with only one year digit, all-numeric serials with a letter in the middle (an example shape is 9414B39332), and serials starting with Z. Those may still be readable using the brand's own documentation, but the public sources conflict enough that a guess could be off by a decade. For a unit like that, look for a printed date on the plate, the original invoice, or the permit record. ICP's 2005 CPSC recall listed Keeprite among its brands and confirmed the letter-year-week layout for units from late 2000 onward.

Who makes KeepRite

KeepRite is built by International Comfort Products, the Carrier subsidiary headquartered in Lewisburg, Tennessee. When Carrier agreed to buy ICP in 1999, the brand list included Keeprite alongside Heil, Tempstar, Arcoaire, Comfortmaker and others. KeepRite is sold by independent dealers and shares serial formats and many components with the other ICP brands.

How sure is this?

Widely documented. KeepRite doesn't publish this code; it comes from recall notices, service literature and inspector references. We tested the icp rules against 15 serials, 5 of them with a date known from a recall notice, a printed label date or the maker. None decoded to a wrong year; codes whose year mark repeats show every possible reading. Always confirm with KeepRite's warranty page before you spend money on the answer.

Quick notes

• Count the characters. Ten or eleven with a letter up front is the modern format.
• A serial that starts with Z, or has a lone letter in the middle of a number string, needs the printed date or paperwork instead.
• KeepRite gives a 10-year parts warranty to the original owner on timely registration, or 5 years if not registered within 90 days.
• If the plate is gone, the indoor coil or furnace may still have its own plate with a usable serial.