You’ll want to look for a production date. This is frequently situated on a label on the exterior of your unit.
If your system is less than five years old, it may still be under warranty. At the same time, warranty terms and conditions vary between manufacturer and installing company.
At Roy Inch & Sons Home Services by Enercare, we can verify your warranty state via a system inspection in London for residential heating and cooling systems, regardless of unit age or manufacturer warranty status.