I bought a harman invincible rs the first of Feb. It was refurbished. It worked great for the past month and a half and 2 days ago I was in the other room smelled smoke went in and there was smoke pouring out of the sides of the stove and it kind of smelled like burnt plastic.. I turned the stove to off and waited a few hours the feed kept spilling little bits out so it took a while, I then took the rest of the pellets out of the hope so it would have no way to keep feeding the stove went out and I left it for 12hrs and came home from work to find out both blowers never shut down and was pumping cold air into the house? the other times I have shut it down to clean it i would turn it to off and in about 40 min it would be out and the blowers would be off? Any ideas what might be the problem?