Finally all fixed. The second shop I took it to said it just needed a regas. Now works fine. I have no idea what the first shop was on about. Heating issue was caused by blocked heater core. Flushed out and the correct coolant added, now works fine although I m still mystified but the logic behind the heating/cooling system. If you set the temperature is that supposed to be able to turn the air conditioning on and off? I can only get that to work by pressing the AC button (snow flake). Thank all for your help.