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Residential Window Warranty Identification

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The Case of the Coverage Question


Dear Glass Detective,

I am seeing internal discoloration in my double-paned windows due to a manufacturing defect, and I am trying to figure out if they are covered under a Lifetime warranty. I found this sticker on top of my window, is there a way to tell who the manufacturer is and if the windows are still covered under warranty from this sticker?

Thank you,

Roger L.
Marin, CA



Dear Roger,

Thank you for making contact with the Glass Detective with your question asking for help in trying to identify the manufacturer of an insulating glass unit that is now showing signs of discoloration. I will try to help but I may not be of as much value to you on this as you had hoped.

Because the sticker that you photographed and sent in was on the outside of the insulating glass unit (on top of the window as you stated) I am going to conclude that it was put there by the window manufacturer as an identity tag (customer, order number, etc.). The only thing I can determine from the sticker is that this particular insulating glass unit was made (or at least processed) in 2003. You state that you may have a lifetime warranty on this unit and I need to tell you that in terms of insulating glass units, warranties rarely exceed 10 years. HOWEVER, if you have some type of documentation that refers to a lifetime warranty, then you should have the name of the supplier/manufacturer on that same document.

Some insulating glass units (particularly if they comply with some code such as a safety glazing code) will have a sandblasted or acid etched logo/tag type marking in one of the corners of the unit itself. These often have a code or symbol of some type that might identify the manufacturer. Also, some manufacturers stamp their logo or name and year of manufacture on the inside of the insulating glass spacer which you can see by looking into the unit and paying attention to the spacer at the edge of the unit.

The best practice in dealing with glass warranties and perhaps all warranties is to keep the original paperwork on file in an easily accessible location. Should your window no longer be covered under warranty, you can use to find local, reliable window replacement companies in your area. Simply type in your zip code, view the profiles of companies nearby, and request a quote conveniently through your computer, tablet, or smartphone. The window dealer will be able to guide you in selecting and purchasing replacement windows that should be defect-free for years to come. They will also be knowledgeable about the warranty programs available and can advise you on what your best options are.

I hope this response is of some value to you and thank you again for contacting the Glass Detective with your question.

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Lyle Hill

Lyle Hill has been in the glass and metal industry for more than 40 years. In this time he has managed glass retail, contract glazing, mirror, architectural window, window film, and automotive glass businesses throughout America. He obtained an MBA from IIT with a focus on Technology and Engineering Management. Hill is also a columnist for glass industry trade magazines and often called the “face” of the glass industry. He has also authored books including “The Broken Tomato and Other Business Parables,” which is available through Amazon. Find out more about Lyle on Linkedin.

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