An air-conditioner is a complex thermodynamic and technical system due to which it can have various problems in its operation. Here is an anecdote on the topic. On one occasion at professional training, a young servicer after a lecture on the newest Multi and VRF LG systems said in panic: „Well, now I don‟t understand anything. I think, that for this, you have to graduate at the university.‟ Of course this is not completely true but the level of professional training is of great importance. The market demands are becoming more and more extensive and devices become more complex. Therefore, you should not repair your air-conditioner on your own without previous consultation with us. If we do not know something, we have a person to ask. Of course, only particular producers and importers have well-organized technical support network.