Possibly the most common problem with modern windows is the failure of the thermal sealed, insulated, double glazed glass unit. Double glazed windows are made of two pieces of glass with an air tight gasket between them. This gasket usually a black or silver color is what fails allowing air to get between the panes of glass.
The most common signs that the glass unit has failed are:
- Condensation is visible between the two (inner and outer) panes of glass.
- It looks like a white powdery substance is coating the inside of the window.
- The windows have a foggy appearance.
- There appears to be a scum on the window that cannot be washed off.
If the window glass appears to have one or more of the above conditions, it has probably failed and will need replacing. Depending on the brand of window, it may be possible to replace the glass unit by simply un-screwing the corners of the sash or removing trim strips and releasing the failed glass unit glass. A replacement unit is then easily inserted into the frame.
Welded vinyl frames, it is often impossible to remove the glass and a new sash unit must to be ordered. On these windows, there is often a number or small tag/sticker on the top or side of the sash (the part of the window that goes up and down) with a code number on it. Using this number you should be able to order a replacement glass and frame without the necessity of having the manufacturer visit the home to measure for a replacement.