[VAC] Re: Rectangle vents and window operators

[RJ.Dial@xxxxxxx]

The opener mechanism has two stages.  As you guessed, the second stage 
is frozen.  Once freed up using many of the excellent methods 
suggested, annual application of something like Lithium grease will 
keep them operating.  

Also, it's a good idea to check the cover attach fasteners too, as 
failure of these is how everyone lose those valuable covers.
RJ