You’ll want to find a manufacture date. This is frequently found on a label on the exterior of your unit.
If your system is under five years old, it could still be under warranty. Having said that, warranty terms and conditions differ manufacturer and installing company.
At Service Experts Heating & Air Conditioning, we can confirm your warranty standing with a system inspection. We also offer HVAC service memberships in Longmont for residential heating and AC systems, regardless of equipment age or manufacturer warranty standing.