I have an Enviro EF1 pellet stove and can't seem to get it to sustain a good flame for more than 12 hrs. I have swept the chimney, cleaned the exhaust motor and the interior of the stove but it doesn't seem to be getting a good fuel/air ratio anymore. Last year it worked with no issues, now it doesn't seem to be doing so well. The bucket is filling with ash and the glass is getting the nasty black soot. Any suggestions as to a fix would be great, I live in Northern NH and its a bit chill up here this time of year.