I first bought this unit in July 2018.  Since then, I am on my third unit for code "FO".  Each unit ran really well for about 8-9 months before failing.  To their credit, I have had no issue with replacement; but, really, three units in the two yer warranty  period?  They need to change their source for the control board.  As long as the unit runs, it is perfect for my situation.  So, to paraphrase  the nursery rhyme, "... When it is good it is very, very good: but when it is bad, it is horrid!"  Here's hoping the latest one will last.