I have a Hudson river pellet stove Chatham model that I've had for about 3 years no issues. Last week I started getting a lazy flame and the burntpot would overfill and even start a fire in the ashpan. I thoroughly cleaned broke it all down still the same thing. The weird part is even if I open the damper the flame doesn't change which was never the case the more open the damper the more intense to flame was but now nothing. Any suggestions?