Ash Build up Question

I have had my Chubby running steady since the end of October. When adding coal today, I noticed a buildup of coal ash in the stove pipe by the Manual Pipe Damper. The buildup is a couple of inches high. I know that the coal ash can't catch fire. Should I shut the stove down and vacuum the rear of the stove by the MPD?

It sounds like a cleaning is needed.

Any horizontal pipe will collect ash. They need to be cleaned before they get to the point that it allows CO into the house.

You can reduce that buildup by lessening the draft pull through the coal bed when you shake.

Close off the air intake when you shake or open the feed door or both.