Magnum Double Hung Windows
Marvin Windows and Doors manufactures Magnum Double Hungs — very large double and single hung windows. One significant difference between Magnum double hung windows and Marvin’s other double hungs is the size. Since most of these units are so large, we don’t recommend that homeowners perform repairs on them.
Problem: Sash movement is jerky.
Solution 1: Check to see if there is paint buildup on the edge of the sash. If paint is sealing the window closed, scrape excess paint off, open the window and sand until smooth. Refinish (leaving the sash open to dry).
Solution 2: Check for a broken balance system. Remove your sash completely and check for the location of the locking terminal assembly. If one is either at the top or the bottom of the jamb, without appearing to offer any support to the sash, your balances are damaged, and you will need to contact your local Marvin retailer for service.