Hello, my King 5500 seems to be burning through more pellets this year than previously, even on the lowest setting. This is the 3d year I've had it, bought it used but it had not been used much. Normal ash, not a lot of clinkers, everything -seems- normal except I'm going through a bag of pellets in maybe 14 hours when it should be lasting at least 20. Cleaned regularly. Every year I go through several different types of pellets, so I don't think that's it. I see in the manual I can reset the control to 'factory settings', I've never changed it, but maybe this is a good idea? Thanks!