On York outdoor units, look for the data plate on the side panel near the electrical connections.
On furnaces, the data plate is usually inside the blower compartment or on the inside of the access door.
The serial number starts with two letters for post-2004 units. If the serial starts with numbers, use the older pre-2004 format.
York, Coleman, Luxaire, Guardian, and Evcon are all Johnson Controls brands using similar serial formats.
Decoded examples
WEMA123456
→ 2019, May
W = 2019, E = May
SHLB789012
→ 2016, August
S = 2016, H = August
NJKC456789
→ 2013, October
N = 2013, J = October
Life expectancy
Expected lifespan: 15–20 years for York central AC and heat pumps. Johnson Controls manufactures York as a mid-to-premium brand.
Common questions
For units made after 2004, the first letter is the year code and the second letter is the month code. Use the year table above — letters I, O, Q, U, and Z are skipped in the sequence.
W = 2019, E = May. Your unit was manufactured in May 2019.
York, Coleman (HVAC), Luxaire, Guardian, and Evcon are all manufactured by Johnson Controls at the same facilities. They use similar components and the same serial number format.
Units made before 2004 used a different serial number format. For pre-2004 York units, the first four digits were the week and year (WWYY format similar to Carrier).