What would cause the combustor to become plugged?

Plugging can occur if the stove is operated improperly.

Examples:

 

Not allowing the combustor to achieve light-off (closing the bypass to soon).  Remember the rule of thumb....when starting a fire in a cold stove, leave the bypass open for 20 to 30 minutes.

Burning materials that produce large flakes or char, such as wrapping paper or cardboard, can plug enough cells to cause smoke spillage. The combustor will struggle to do its job.