You’ll want to find the date it was made. This is frequently located on a label on the surface of your system.
If your equipment is newer than five years old, it may still be under warranty. Having said that, warranty terms and conditions vary between manufacturer and installing company.
At Service Experts Heating & Air Conditioning, we can check your warranty state via a system inspection. We also have HVAC service memberships in Kingston for residential heating and air conditioning units, regardless of equipment age or manufacturer warranty validity.