Yesterday when I went out for the first load of the year my flow meter decided to quit.  It probably quit over winter but when I checked things out this spring I didn't watch flow, I just ran water through it on the yard and thought I was good to go.  After trying my 3" meter and getting things to work I replaced the 2" meter and away I went.  What goes wrong in the meters?  The impeller still spins and it was clean.