How old is my Day & Night unit?
Day & Night is part of Carrier Global (ICP). 1 serial format sourced across central air conditioner, heat pump, furnace, packaged unit.
Serial number decoder for Day & Night
Type the serial from the data plate, not the model number. Nothing is sent anywhere; the tables are in this page.
Format example: 4006A17330
- Day & Night air conditioner serial numbers in the 1980 to present format encode the year as digits 3-4 (2-digit year; century by context, 1980+) and the week as digits 1-2 (01-53) (source: building-center.org).
- Example: serial 4006A17330 decodes to week 40 of 2006.
- Day & Night's official lookup at dayandnightcomfort.com returns warranty / registration lookup.
Decoder pages by product
Format eras
- 1980 to present VERIFIED
####A#####Central Air Conditioner, Heat Pump, Furnace, Packaged Unit
Official lookup: the authority
Open the official Day & Night lookup takes serial number; returns warranty / registration lookup; URL verified live
This site is a reference built from published tables. The manufacturer's own lookup wins whenever the two disagree.
What we could not confirm
- Historic Carrier/BDP brand, now marketed by ICP (icpusa.com our-brands). Styles 4006A17330 (WWYY-L, Carrier style 1) and 850304091 (YYMM 1980s). NOTE dayandnight.com is an unrelated company; the HVAC site is dayandnightcomfort.com. Building-center calls 4006A17330 'nine character' - it is ten.