You’ll want to look for a manufacture date. This is usually situated on a label on the surface of your system.
If your equipment is under five years old, it might still be under warranty. Having said that, warranty terms and conditions vary between manufacturer and installing company.
At Boehmers/Cronin Emery Service Experts, we can check your warranty status through a system inspection. We also provide HVAC service memberships in Kitchener for residential heating and cooling units, regardless of equipment age or manufacturer warranty status.