I try to bleed it today but When Icome to a stop and REV the Engine Up, then Hot air comes out but when the Rev comes down, the cold air comes out again. Heat Valve can be tested outside the System. I won't change it until I am 100% sure that is bad. Core being clogged is a possibility but when you get hot air at all, kind of makes me think that is OK.
I froze my rear this morning.