You’ll want to look for a production date. This is usually situated on a label on the outside of your system.
If your unit is under five years old, it may still be under warranty. However, warranty terms and conditions vary by manufacturer and installing company.
At Peitz Service Experts, we can verify your warranty status with a system inspection. We also have HVAC service memberships in Pierre for residential heating and cooling systems, regardless of system age or manufacturer warranty standing.