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York Serial Number Decoder

Equipment FurnaceCentral air conditionerHeat pump Brand

Serial number Find the age

How to Read the Serial Number

1. Find the data plate: on the outdoor unit's side panel, or inside the furnace door.
2. Check the pattern: letter, digit, letter, digit, then six digits (made late 2004 or later).
3. The second character is the decade digit and the fourth is the year digit: 1 and 6 make 2016.
4. The third character is a month letter, but references read it differently, so treat the month as unknown.

York serials from before late 2004 use a code that repeats, so the year can't be pinned down from the serial alone. Check the plate for a printed date.

Codes based on a week number give the month only approximately. If the plate prints a manufacture date (often labeled MFG or MFD), trust that over the serial.

How Long Does It Last?

Source: InterNACHI Standard Estimated Life Expectancy Chart. Maintenance, water quality and climate all move these numbers.

Age doesn't mean a unit has to be replaced; it tells you when to start planning. A replacement you schedule costs less than one you buy the night it fails. If it's near the end of its range, write down the model, serial and capacity now, so a contractor can quote the right replacement without a trip just to read the plate.