I moved into a new house a couple months ago and it has a LDJ-620-10 a-maize-ing heat furnace. It was running good at first, I thought, I don't really know anything about them except what I read in the manuel. It had problems with the fire going out, which could have been user error but now the auger is not feeding it enough corn to keep a fire going for long. It was overfeeding it but I haven't adjusted anything. I took the auger off and checked for clogs but there is none. How do I adjust the feed rate? Also why would it of changed by itself?