I am trying to help my father out with his stove. It has a good flame, but it builds up lots of ash and does not seem to heat so great. He keeps the stove on 5-5. We have thoroughly cleaned in inside and out along with the blower and components. It has new auger motors and a new control board. He does not use the corn auger in the stove and it is set to pellet mode. Any help to reduce the ash and increase the heat would be appreciated. Thanks