Submit a serial number
Didn't decode, or the date looks wrong? Send it. The most useful submissions include the date printed on the label, if there is one, since that's what lets us confirm a new format. Read how serials become tests.
Your serial
Send it with the brand and equipment type. Every submission is checked by hand and, once resolved, becomes a test the decoder must pass.
Email the serial number, the brand, and whether it's a water heater, furnace, AC or boiler to support@factorydate.com.
If the label prints a manufacture date, include it: that's what lets us confirm a new format. A photo of the plate helps too.