Think I have got to the bottom of it...I think the engine is just not getting hot enough...

When driving, the temp is sitting around the M mark, so around 1/4...the air comes out warm

When sitting in traffic or when the temp goes up, to around the N-O mark, which is around 1/2 and a bit over, the air gets hot to what I think it should be

Ill live with it for another week as next weekend I should start pulling the engine out!