I think I have a fan issue?? pdv new englander

[flickerstick]

Ok the story ..pdv used stove possibly 2000. Functions ok.. not a lazy flame but not very excited either. Changed exhaust blower(brand new), new gaskets, cleaned stove very well. Stove runs ok up to heat setting 5. decent out put about 220 degrees but still not a angry flame. My pipe was too long , using the EVL formula i was a 19.5 now im down to 13.5. this helped but only a little. My guess is still not enough air?? So heres the big question..if the stove is close to 8 years old could the board not be sending enough juice to the fan?? There is no obstruction everything is replaced, lubed and working. But after setting 5 the pellets mound up, the flame gets lazy and its all down hill from there. I know about the LFF and LBA but those are for settings 1/2 on the heat range and have no affect after setting 3 and above. I know somethings up because people are running their stoves on one and two and getting good heat. Does anyone know what voltage should be seen at the fan?? I only assume the voltage would increase to supply more air as the demand for pellets increases?? IE; setting one low pellets no need for alot of air. Any help would be appretiated, its getting cold in mass!