my grandmother has a cmf miller gas furnace with electronic (hot surface) ignitor. propane. I installed it for her 4 or 5 years ago. didnt have heat a week ago so i looked at it. wouldnt ignite so i replaced the ignitor. worked fine for a little while but she then called later and said it made an awful boom. tried reajusting the ignitor, there is no adjusting the gas valve i dont think. wasnt sure where to turn. so she called a "pro" and he was there twice and charged her 85 dollars and it still does it. any ideas.doesnt do it all the time, it seems to be on really cold nights when it cycles on and off more frequently
Anytime A Furnace "Booms" Upon Ignition Normally Means There Is An Abundance Of Gas Build Up, Pre-Ignition.
Not Very Familiar With Miller - But Most New Burners Have Paper Thin Slots on The Front Sides of The Burners. This Allows One Closest To The Igniter To Light The Next One, Which Lites The Next One, Etc.
If It Is In A Dusty Area - or Located Near A Dryer, That Paper Thin Slot Begins To Build Up Debris. In Event, Will Cause An Explosion During Ignition - and Will Only Get Worse.
I Would Recommend Having Her Unit Cleaned - and Have Them, Remove & Clean The Burners