Fog or haze between window panes may point to a failed seal in the insulated glass unit, but appearance alone can’t confirm the cause or show whether the whole window needs replacement.

Check where the fog is

Look from indoors to see whether the haze appears trapped between the panes or on the room-facing glass. You can gently wipe the accessible interior surface to check; don’t dismantle the window. If the fog remains between the panes, a window professional can assess the glass unit and explain possible options.

When to get a professional assessment

Contact a window professional if the fog stays between the panes, returns, or interferes with your view. It isn’t possible to confirm the cause or the right scope of work from the appearance alone.

What to ask about the work

Ask whether the assessment covers the insulated glass unit as well as the full window, what findings support the recommended scope, and whether the quote specifies exactly what will be repaired or replaced. Continue to Window Installation for the mapped provider path, and confirm the company handles your type of window.

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