Whirlpool Heat Pump Date Code Help

[Robert Foster]

Whirlpool heat pumps are not in the usual data base I use. Can someone please
help me with deciphering these.

Outdoor coil 1603G40400
Air Handler 6005E46764

Thank you

[Mark Reinmiller]

Whirlpool heat pumps are not in the usual data base I use. Can someone please
help me with deciphering these.

Outdoor coil 1603G40400
Air Handler 6005E46764

Thank you

It would help if you have a rough idea of the age. I am not familiar with that number series, but as a guess it could be 2004 based upon the 4 in each number after the letter. Since 2003 Lennox has produced equipment under the Whirlpool name for Tradewinds Distribution LLC, a subsidiary of Watsco Inc. I believe that Heil-Quaker stopped using the Whirlpool name in 1987. I'm not sure if it was used between those dates.