Hi, I also have in history this error 801228. It means a reduction from fan power. I got scared the first time when I saw that, but my friend told me this was ok. This is overuse of the aircon, and I have to change it or to fill it up. The
aircon servicing price is not so expensive, significantly when you change it once a year. Experts also recommend changing the aircon every year, because of removing all these bacteria and dust. I hope I have helped you. By the way, I recommend you to see an expert if the problem isn`t removed. It could get worse.