There are three things you need to know in order to determine if your system is under warranty:
- The brand of your unit
- Who the distributor of your brand of equipment in your area is
- The serial number of your unit
Once you find out you have a Trane or American Standard or Lennox or whomever made your unit, you should be able to search your brand's site for local distribution. You can also try a search just for your brand and state you live in. (Carrier Ohio or Carrier Ohio distributor)
Now that you have that information, you should be able to call them and just provide the serial number of your unit so they can verify if you are still under warranty or not. It never hurts to have your unit's model number too and since they are both located in the same place, it's simple to get both.
Furnace Rating Sticker Image
How Do I Find The Model And Serial Number For My Furnace And Air Conditioner?
Most furnaces have their unit information inside the top section of the unit listed on the sidewall. If you take the door off and look left or right, you should find a sticker or plate that will have both these pieces of information. NOTE: If you have a down flow unit (air blows down from the unit, not up) your information may be in the lower compartment.
Your air conditioner or heat pump however will usually have it's sticker or plate mounted on the exterior of the unit for easy reference. Your hope here is that the weather hasn't rendered your label unreadable. Unfortunately, not all information plates are etched in metal and ink labels tended to fade over time.