Haiz, my aircon has the same problems too. Mine is a 3 in 1 unit, and after installation, the aircon in my master bedroom is not cold after a few days. Then we called the installer back again, but he says that the problems might lies with the aircon unit. So we called the P****** company, and they sent their technicians down and do so test but the problems is still there. Then the piping started leaking water, so we called the installer down, and he changed the piping but the problems remain, so used newspaper to insert into the casing and claimed that the leaking is due to the condensation. Then newspaper does not work again, he had no choice but to use spray into the casing, but it still does not solve the problem. After that, whenever I called him, he just dun answer my call.
Till now, I am already so pissed off with that problems. I can't paint my walls becos of the stains marks of the leaking water from the pipings. And I could not even put my bed or TV near to the walls too.