Oh ok I have the trim dial starting at zero at the top and I can either go to the left -1 to -4 or go to the right +1 to + 4 the manual doesn't explain much in detail for pellet burner dummies so my thought was negative side less air and positive side more air.Maybe too much draft? I would put all the trim screws in the middle of their adjustments to start....then adjust the draft stick
My PelPro isn't the same model... It has 3 trims I can adjust and a draft stick that I can pull or push to adjust the flame.
I run the fan trim at about 1/3 it's full speed