Air Con not blowing hot and cold

I'm a rangie novice but im willing to learn if it means saving myself money. I had my first p38 for two weeks now and have only just noticed that the AC isn't working correctly. The rate at which air is blown into the cabin works as it should according to the display but there dosn't seem to be any change in temperature when i turn it from hot to cold. Also the little book sign appears sometimes but mainly when i turn the AC off. Any help guys?

You could have the gas checked at a Kwikfit-type garage - they don't charge if regas doesn't reduce temp by at least 10% and any leaks will show up on the pressure test. Costs about £50 I think, but no charge if it doesn't work. Otherwise, find someone in the area with a Faultmate and have the codes read and checked out - may be blend motors packed up if the condensor is ok and there are no leaks, and gas levels are normal.

The climate control on the P38 is the most complex system I have had on any car, with blend motors, sensors, relays etc.

As stated, start by the cheap stuff, re-gas, if that doesn't fix it, get the faults read then dig in your pockets