[Resolved]  LG Electronics — error ch 38 and ac not cooling at all

We purchased 3 lg dual inverter compressor at once and it was installed. The 2 are working somewhat fine but the one in our sitting room has been showing error ch 38. We have not enjoyed cooled air for one day and its been so long already. We buy all our electronics from lg but this is a huge disappointment. I really need this ac to be fixed. It has literally never been used.