Thanks for the replies.
My auger is short, only about 4ish feet, but there are holes. As soon as I stop burning I will investigate the holes and see if they are clogged. I hadn't considered the air settings as a cause. I burn rice coal. I usually have the air setting a little above 5. If I lowered it do you think that would help? I don't really know if it has always been a problem because of the chimney issue when we first installed it. The chimney wasn't tall enough so it wasn't sucking. I had the chimney professionally heightened, cleaned, and repaired. They checked everything and made sure the boiler was venting correctly out of the chimney. Do you think if I used only dry coal it would help or wouldn't it matter. I also had not thought of a lid but that doesn't seem to address the problem, just cover it up. Where would I get a longer auger and pipe if you think that would help?