You’ll want to check for the date it was made. This is usually situated on a label on the exterior of your equipment.
If your equipment is newer than five years old, it could still be under warranty. Having said that, warranty terms and conditions differ manufacturer and installing company.
At BW/Cook Service Experts, we can confirm your warranty status via a system inspection. We also have HVAC service memberships in Elkhart for residential heating and AC equipment, regardless of equipment age or manufacturer warranty status.