I have some double pane windows with failed seals. They get condensation inside. When it dries it leaves unsightly residue that I can't figure out how to clean off.

I know that I could replace the windows, but that seems wasteful for what is mostly a cosmetic problem.

Are there any clever ways of cleaning between the panes? Maybe all windows should come with magnetic cleaners like they have for the inside of fish tanks.

  • 1
    It is a cosmetic problem, but the window is now not as energy efficient, so there is that to consider as well. The windows aren't going to come with a magnetic cleaner because that would be admitting that the window will eventually fail.
    – JPhi1618
    Commented Apr 15, 2016 at 13:59

3 Answers 3


In fact, you can clear these windows up. If its regular glass, two small holes are drilled and a cleaning solution (which need not be toxic) injected.

If it is tempered glass, the same procedure is possible if the glass seal can be reached for drilling (this is possible for most windows that can open and close: they'd get drilled from an edge). Check the glass for a frosted or white color marking showing if it is tempered.

Since this is a DIY advice site I can direct you to http://foggywindowrepairkits.com/ . The DIY kits mentioned above are over $200, and can't be rented and returned. But really you're probably better off finding a local service company that can do this, possibly with even better techniques.

  • These are tempered, and they are fixed windows that don't open, so this may be limited in my case. Commented Apr 20, 2016 at 17:18

No. You're limited by what you can do from the outside, and obviously that's not much.

Energy efficiency is only slightly reduced in such cases, as airflow into and out of the compartment between panes is minimal, but the aesthetic problem will only get worse.

Chances are you can replace just the sash, which might cost about half of what a new window would and doesn't require carpentry work aside from a little hardware swap.

  • These are fixed windows that do not open, so I believe I would need more than a sash for these. Commented Apr 15, 2016 at 14:56
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    You might be surprised at how easy it is to remove a fixed sash. Contact the mfr.
    – isherwood
    Commented Apr 15, 2016 at 15:12
  • This is incorrect, as there are options for in-situ cleaning between the panes.
    – Bryce
    Commented Apr 20, 2016 at 17:21

I have had the same problem with vinyl frame windows. There is nothing you can do except replace the window. With vinyl windows, you can usually replace the entire sash quite easily. Contact the manufacturer or the contractor that did the orignal install. Most manufacturers offer a warranty against fogging for a certain number of years, so be sure to check that as well.

I actually took my windows to a glass shop. They removed the glass and replaced it with a new double pane in the original vinyl sash. This might be cheaper than purchasing a whole new sash, or if the model has been discontinued.

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