You’ll want to check for a manufacture date. This is typically found on a label on the surface of your unit.
If your system is less than five years old, it might still be warrantied. At the same time, warranty terms and conditions vary between manufacturer and installing company.
At Strand Brothers Service Experts, we can check your warranty state through a system inspection. We also have HVAC service memberships in Austin for residential heating and cooling units, regardless of system age or manufacturer warranty standing.