Keeps throwing a h1 code. Ran it all last year with no problem. Stove is very hot. I'm noticing a lot more ash with the same pellets i used last year. Flame is real tall and when I adjust the damper the flame doesn't change. The damper as always been wide open and I'm noticing a lot of creosote in the burn area. Clogged vent? I also noticed the door gasket is messed up in the area both ends came together. Help any ideas? Thank you