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Insulated Windows: How to Tell If Their Sealing Is Failing

Now that the weather’s getting chillier, you need to make sure heat isn’t leaking out of gaps in your exterior. Otherwise, you might get a higher power bill this fall. Your windows are one of the most vulnerable parts of your exterior, so it’s a good idea to start with them. 

Renewal By Andersen® of Long Island, your go-to company in the state for windows, shows you how to check insulated windows for leaks below. 

What the Sealing Is For

The sealing makes sure the argon, which blocks the transfer of heat, between the two glass panes doesn’t leak out. If the sealing has been damaged, argon will leak out. Moisture then enters and forms condensation in the space between the glass panes. 

Foggy Glass 

Keep in mind that condensation sometimes forms on the window glass surface due to excessive humidity inside your home. But if you can’t wipe it off, the condensation might be between the glass panes. 

Glass Distortions 

Argon leaking out can also cause some parts of your window to collapse. In some cases, however, the distortions are barely noticeable. While inspecting the glass for any distortion, compare your reflection with the reflection in a mirror. 


A leaky window could also be the culprit behind a higher-than-usual power bill. Check if other parts of your home are colder than others. 

Here’s another trick: close all the doors and windows. Light an incense stick and place it near your windows. The smoke should move towards the leak, if there are any. 

What to Do Next?

If you find a leak, we recommend getting a window replacement. Repairs aren’t cost-effective because they can only plug the leaks, not refill the gas and restore your window’s energy-efficiency. Replacing the glass panes isn’t viable either, especially since it costs just as much as a new window. To make sure your new windows last as long as your old one, only hire reputable contractors. 

Looking for reputable contractors in your area? 

Renewal By Andersen® of Long Island offers a wide variety of premium specialty windows. To get a free estimate, call us at (631) 206-6773. Or leave us a message on this form. We serve homeowners in Huntington, New York. 


"I was very impressed with Renewal by Andersen. They showed up in time and we received several follow up phone calls as the installation was being done as well as the sales representative stopping by to check in on the installation. The delivery/ installer was very professional. I would highly recommend Renewal By Andersen."

February, 18

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