You’ll want to find the date it was made. This is typically situated on a label on the outside of your system.
If your system is under five years old, it may still be warrantied. At the same time, warranty terms and conditions vary between manufacturer and installing company.
At D & K Heating Service Experts, we can confirm your warranty state through a system inspection. We also provide HVAC service memberships in Belleville for residential heating and AC equipment, regardless of unit age or manufacturer warranty validity.