Coldest day of the year and my climate control has a mind of its own throwing cold air out while driving around the city. Changing the temp makes no difference but on faster roads I get hot air but side windows are steamed up indicating no air con. Everything on the display looks to be working OK. Also coolant warning bleeps every 5 days or so and I need to add about a litre each time. Car was in the dealers for this problem three weeks ago and they replaced the head gasket - obviously this didn't fix the problem (Car is only 1 year old and this didn't seem right at the time). Anybody any ideas?