Same here , lol . I finally just removed the knob , and kept it in the T@B "toolbox" incase I ever need it to manually open the vent . Installed a little black rubber cap over the crank for the knob so it looks a little nicer .AnOldUR said:Had to remove the knob. Kept hitting my head on it.rcarlson1957 said:... can be opened and closed manually too (has a knob).