Common replacement parts for aluminum windows include the upper and lower sash, exterior sill, apron, side jamb and interior casing. Other parts that are commonly replaced are the window's balance and latch, locks, levers, handles and cladding.
When an aluminum window malfunctions, the first step to repair is identifying what part is causing the malfunction. This might mean removing the entire window to discover the problem, leaving a gaping hole until it can be repaired. Once the problem part is identified, attempt to find the part at local hardware stores or specialty window shops on the Internet. If the part won't arrive in a timely manner, the window should be replaced. Unfortunately, the window may not be sealed properly, leaving the home vulnerable to damage from leaks.
Replacement parts that perfectly fit aluminum windows can be difficult to find if the window is an unusual shape. These shapes include sliding glass doors, as well as storm, awning, glass block, double hung and casement windows. Purchasing parts that do not fit the windows can make them impossible to reinstall correctly. If the installation is completed, the window may not work; if it is not, the window remains unsecured and in danger of leaking until the right part can be ordered.