I'm working on a englander 25 pdvc pellet stove. I was called because the customer said they needed a new combustion motor, which I tested and was fine, the determination was made that the control board was bad. I had a used control board that I installed, after a day the customer called and stated that the flame goes down and almost dies out and then the flame gets higher and continues low then high. They like running it on 3 so I watched the lower auger deliver the Pellets and it will push alot of Pellets out on a turn then the next turn it may push 3 or 4 out, the next turn alot more Pellets and then another turn a large group. Due to the pellet delivery being like that, the flame goes up and then almost dies out. And it continues like that..any help would greatly be appreciated. ..