Made the biggest mistake putting my huge heavy king size in my top load machine (the kind with an aggitator). It chewed the edge of my quilt. Ruined and I could have kicked myself. Won't do that again.
In fact, I told my husband that when my old machine dies, I was getting a front loader because we have so many quilts on beds every day of the year. I use a gentle wash, cold water and spin on high. Throw them in the dryer on high all the time and none have damaged. Depending on the weather (Florida) I will also hang them on the line to get that fresh crisp scent.
I was once told from a quilting guild that one should NEVER WASH A QUILT! and that all the quilts in their museum have never been washed. They are a few hundred years old. I doubt I would want to put one on my bed that's never been cleaned. Now I can almost bet that everyone here washes theirs. Families are too active these days and getting body odor, sand, soil and food stains on a quilt will ruin it more than not washing it at all. Similar to a carpet. Can you imagine taking a huge whiff of one that was never cleaned?