We too purchased Hitachi Split ac 1.5 ton, 5 star rating it works fine for one night and next evening, ac was not giving cool air, only fas was working. We called the person. who fitted the ac. he came and filled the gas again without knowing the fault. Again after 2 days, same problem arises . and same person came. but he was unable to spot the leaked position.
So the shop person called hitachi customer care and they sent their representative. They came and checked the outdoor and undoor unit thoroughly and found problem in joint in indoor unit. They welded that joint and no problem came after that.
Things which i don’t like about Hitachi: No display on indoor unit.
Like: Its cooling power, chilled even at 25 degree during hot days..
Overall, I am happy with Hitachi.