Aircon blows hot air unless set to 10deg

Lately my air-con gave in, unless it's set to 10deg hot air comes out. At 10deg the air is cold as it should be. I'm not sure it needs re-gassing as this was done and upgraded to lpg? two years ago. Why is this and what to do?

For example; 10deg cold, 15deg hot air emerges.

 

Maybe the actuator motor is playing up . Or maybe the tap ?

 

hm good thinking, i'll see if i get any codes from conZult.