ApplianceAge by CarWhere
How old is my HVAC unit or water heater?
Every furnace, air conditioner, heat pump, and water heater encodes its manufacture date in the serial number on its nameplate. Pick your brand, paste the serial, and get the build date, age in years, and how it was derived — free and instant.
Free. The serial is on the metal nameplate or rating label, usually near the bottom of the unit.
How serial-number dating works
Find the serial
On the metal data plate or rating label, usually near the bottom or side of the unit. Labeled "Serial" or "S/N" — not the model number.
Pick the brand
Each manufacturer encodes the date differently, and several brands share one ruleset (Bryant and Payne decode like Carrier).
Read the date
The decoder shows the manufacture date, age, confidence, and the exact positions it read — so you can check it yourself.
Decode by brand
Frequently Asked Questions
How do I tell how old my HVAC system or water heater is?
The manufacture date is encoded in the serial number on the unit's nameplate. Each brand uses its own format — for example, Carrier encodes the week and year in the first four digits, while A. O. Smith water heaters use year then week. Enter your brand and serial in the decoder above to get the date instantly.
Is the serial number date the same as the install date?
No. The serial number gives the manufacture date — when the unit was built. Equipment is often installed weeks or months later, and sometimes sits in inventory for a year or more. Use the manufacture date as the lower bound of the unit's age.
Why does the age matter?
Age is the single best predictor of remaining service life. Gas furnaces typically last 15–20 years, air conditioners and heat pumps 12–17, and gas water heaters 8–12. Knowing the manufacture date helps you plan replacement, judge a home inspection, and value a used unit.
Serial-number decoding is approximate. Results are estimates based on published manufacturer formats; always verify against the manufacture date printed on the unit nameplate. ApplianceAge is a CarWhere tool and is not affiliated with, endorsed by, or sponsored by any manufacturer. Brand names are used only to identify the equipment a serial belongs to.