All, while driving earlier in my Gti CS heater on with air getting sent to footwell and up top, dawned on me my left hand was getting cooler and for whatever reason the centre vents had started sending cool air without me touching it? Kept getting same warmth from driver side vent and had a fiddle changing the settings to windscreen and swapping back etc but couldn't get warm air back out of centre's??
I've had a search on here but only found something via google on golfmk7.com referring to and I quote..."blocked flaps"

......is this likely, do these operate off sensors to open and close?