All of my 20 year plus Anderson windows are difficult to open and won't close close enough to latch them. A few years ago my neighbor had a handy man out and he forced water somehow through the bottom of the window and cleaned out years of gunk and all of her windows worked great after that. Is anyone familiar with how to do this?
It should be just hosing the window from the outside around the entire perimeter to get any gunk out for restored smooth operation. For windows closing fully and locking easily, it's normally just wiping the tracks clean.
I've even simply found and, of course, removed pens, pencils and bits of mini-blind cord caps that rolled into or got crushed by the window in the tracks to completely fix quite a number of long-time problematic windows.