Most Andersen® Windows and Patio Doors will have an etching on the glass that identifies key features about the window or patio door.
Identify Window or Patio Door Glass Features
This article will help you identify common glass codes that tell you the type of glass, manufacturing date, if the glass is tempered, or if your unit has an FX-Number. This information is also helpful if you plan to Contact Andersen® Windows and Doors requesting replacement parts or to answer questions related to your window or patio door.
This Article Will Help You:
- Locate the Andersen® glass logo.
- Identify glass type.
- Identify window or patio door vintage.
- Identify the tempering code.
- Identify the FX-Number.
Let's Get Started
1. Locate the Andersen® Glass Logo
The first thing you should do is locate the Andersen® glass logo and details that are etched directly onto the window or patio door glass. It is typically located in one (1) of the lower corners of the window or door, but can also be in one (1) of the top corners.
Note: The logo can be difficult to see at times. Try these steps to improve visibility:
- Use a magnifying glass to enhance small details.
- Take a digital photo and zoom in on the image.
- Shine a flashlight across the glass to highlight the etching.
- Hold a dark piece of paper behind the glass to reduce glare and improve contrast.
Identify Glass Type
You will see a series of letters and numbers indicating the glass type on the etching. The Andersen® logo does not always indicate that a window or patio door has specialty glass. Tinted or patterned glass types will not be marked. This notation varies by glass type and may include, but is not limited to: HP Low-E, High-Performance (HP), HP Sun, HP Smart Sun, and Dual-Pane Clear.
See Glass Types Available for Andersen® Windows and Patio Doors for more detailed information about each glass type.
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Example of a Low-E Glass Code
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Identify Window or Patio Door Vintage (Manufacturing Date)
Andersen glass logo etchings will include the product's vintage, also known as the manufacturing date. That date tells you when the window or patio door was made or when a window sash or door panel was replaced. On etchings that match the image above, the vintage is identified on the right-hand side of the logo, where YYMMDD (YEAR, MONTH, DATE) is listed. You'll see this style, YYMMDD, on newer windows and patio doors.
On older glass windows or patio doors, the vintage may appear differently. An easy way to find the manufacturing year in these logos is to look for two (2) numbers grouped together (for example: "06," "99," "95). For additional logo examples, see Glass Types. 
Example: The glass logo to the right shows another way a manufacturing date may appear in the glass etching. In this image, the vintage is on the right-hand side, but listed as 1-06. This means the window or patio door was manufactured during the first quarter of 2006.
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Example of a Glass Code Vintage Location
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Identify the Tempering Code
Depending on the window or patio door type, the unit may have a tempering code etched into the glass surface. The tempering code does not identify the glass type. For more details about tempered glass, see Tempered Glass Information.
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Tempered Glass Code
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Identify the FX-Number
Since 2002, Andersen has etched an FX-Number onto the glass of Flexiframe®, Arch, and Springline™ units to easily identify that it is a Flexiframe® product. Monolithic Impact-Resistant Glass will not have an FX-Number etched into the glass.
If your window was manufactured before 2002, the FX-Number could be located underneath the sill stop or on the Product ID label. The sill stop is typically wood trim that frames the bottom side of the window. See How to Install an A-Series and 400 Series Casement Operator for a video on how to remove the sill stop. To locate Product ID label, see Identify Your Andersen® Window or Patio Door Using a Product ID Label.
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Example of an FX-Number on the Sill Stop
Example FX Order Number on a Product ID Label
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Contact Andersen® Windows and Doors if you're unsure about the glass type or where to find the Andersen® logo.
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