From
this link. On my 6600R the rain sensor has an On/Off switch to disable it.
In this picture the cabinet is the back and the ceiling light is the front.
Back left - round black item is the POS glass fuse. the fuse needs to be removed during storage - parasitic draw
Back right - 3-way On/Off switch for the fan - In/Off/Out
Front left - blue/green teardrop sticker that says "rain sensor equipped"
Front right - knob for manually opening and closing the cover. Hiding behind the base of the knob is a red and black label for the switch that turns the rain sensor on and off.
In short, you can have a Fantastic Vent fan with a rain sensor and not use the rain sensor option.
