I installed a bunch on Simonton VRW about 6 years ago. The vinyl frame has
a lifetime warranty and the windows themselves have a decreasing warranty
that goes out about 50 years. The first 20 years are 100% covered.
A couple of weeks ago, during that really hot spell that most of us went
through, one upper sash began to fog up between the panes. I called
Simonton, gave them the bar code number from the side of the sash and about
a week later the replacement sash showed up on my doorstep.
No questions asked, no hassle, no request for the old sash back.
Gotta give credit where credit where is due.