You’ll want to find the date it was made. This is typically located on a label on the outside of your equipment.
If your system is newer than five years old, it could still be warrantied. However, warranty terms and conditions vary between manufacturer and installing company.
At Fras-Air/General Service Experts, we can confirm your warranty standing via a system inspection in Hillsborough for residential heating and cooling equipment, regardless of unit age or manufacturer warranty standing.