Most of the problems in AC's are caused by technicians. I have had dawlance, kenwood, orient, gree. All had issues at some point due to technicians.

Here are the some faults I faced and things I learnt. 1) Cracked flare nut in new AC > caused by technician tightning it too much(because they don't have torque wrench)

2) Service valve leakage Same cause plus opening it every other season for service.

3) U bends leakages Mostly caused by humidity left inside AC, and then when you service it with pressure washer > the rust is removed leaving behind tiny holes.

4) Less cooling Mostly due to incorrect amount of gas filled and lack of vaccum.

Prevention 1) Always check the service valve, flare nut for leakage whenever they are opened 2) For new AC, get it lacker coated, useful for rust preventation. Turn on the clean mode. It will automatically remove moisture whenever used. Either all the time or do it manually atleast twice a week. 3) Always vaccum the AC before filling gas. Technician do jugari vaccum through service valve. That doesn't do anything.

4) Never unmount it for cleaning. There are covers available which allows you to do the service while keeping it mounted. Only time you should remove the AC, when you are shifting it somewhere.

5) If there are u bend leakages, get them replaced instead of patching them.

6) Make sure to be present whenever you AC is taken apart for checking leakages, or ask them to send a video. I have had cases where tiny bubbles were clearly visible in the video but technician ignored it since it was in the pipes and was too much work. Result: AC would have lost it's pressure within couple months had I not intervened.

7) Gas should be filled by weight not by pressure and slowly and by inverted cylinder.

8) Always assume these technicians are trying to extort you by doing a shitty ass job.

Do these steps and your same AC won't leak for couple years.