You’ll want to find the date it was made. This is usually situated on a label on the surface of your system.
If your equipment is less than five years old, it could still be under warranty. However, warranty terms and conditions vary between manufacturer and installing company.
At Teays Valley Service Experts, we can check your warranty standing through a system inspection. We also have HVAC service memberships in Hurricane for residential heating and cooling equipment, regardless of unit age or manufacturer warranty standing.