Originally Posted by HighlandPete
Perhaps they think the PTC electric element in the diesel's HVAC system is good enough for the climate in the UK and Ireland.
Ive been experimenting with mine since the temps have started to drop over the last three weeks or so (a few times when its been under 3 degrees). The only time I can get the PTC to work is when the car is first started and I select window demist to get rid of frost, after a minute or so slightly warmer air is blown at the screen and side window vents, enough to melt the ice but not what I would call warm. Once the front window demist is deselected I get no warm air until the engine oil temp is about 50-60 degrees then the normal heat comes out form the vents and gets hotter as the oil temp reaches 100 degrees. Ive come to the conclusion that its just to aid demisting while the engine warms up.