So, my Enviro Mini is giving me problems (again). The pellets will light initially, but won't stay lit (it goes out after about 15 minutes). I cleaned it thoroughly & everything SEEMS to be working properly, I just can't figure out what might be wrong. Any ideas? My driveway isn't passable right now, so I don't think I can convince a pro to come and look at it, even if I did have the $$, so any suggestions would be much appreciated! It's a new brand of pellets (Okanagan) but I have burned about 15 bags with no problems before this happened.