One thing nobody has asked, and maybe you don't know,
but do you have any idea what the temps of the stove are running?
If it's the same vigilant that vc has it's owner's manual on line, they show
a top thermometer, with expected readings from 400 to 700 degrees. That may
give us an indication of how the stove is performing,, then we can go
into moving air around the stove etc. If your stove isn't coming up
to temp, we can look at coal/draft issues.
If the stove is up to temp, then look at location, and airflow around