Hello! We have a quadra-fire pellet stove. New last year & it worked great. Since the first start up of the season this year, we have had some issues. It seems that the pellets aren't feeding regularly into the stove. We are hearing pellets dropping about every 5 minutes, not continuously, so the fire burns out-5 minutes later, pellets drop and we're back to a good fire-for only about 3 minutes. Any advice?