I have a 2013 Enviro Mini A and have a problem with High/Low mode. I can get it to start just fine but the flame appears to get smothered in low mode after a random period of time and shut the stove off. I have noticed this once when I heard my electric heat kick on in the middle of the night (a signal that the stove was not running). Another time I can home and the stove was off. Both times the burn pot liner was overflowing with pellets. I tried adjusting the feed trim in various settings and ultimately level 1 but the fire would still smother. The combustion blower is on level 4. Any ideas on what else I can try?