I have an older Quadra fire Mount Vernon AE it has random misfire issues some times it happens three times a day or may not happen for two or three days it goes into start up mode and glow bar is on for seems four or five minutes and then it does an auto clean goes back to start up mode and lights just fine stove may light fine for next several startups then out of the blue same issue stove has been throughly cleaned everything even the intake side new igniter newer combustion fan HELP