Purpose
GW / GS packaged rooftop water source heat pumps are include two serial numbers. For parts and technical support, each one may play a unique roll and having the correct information at hand helps to ensure timely product support.
Key Information
On the corner post closest to the electric panel, you will have a large rectangular serial tag similar to the image below. The serial number located on this tag is helpful in some cases for parts ID, but for the most part isn't necessary.
Located a few inches above this is a secondary label which includes the serial number required for parts and product support requests.