About 3 weeks ago I built a new hot roaring fire with some yard scrap....in less than 15 minutes the stove starts whining with airflow like a turbine engine, with rapid whuffling ignition and flame sounds coming from the flue pipe above the stove...within 3 minutes more, the flue pipe started to glow: deep red and getting noticeably orange. I cutback the secondary thermostat control to minimum air intake, to no effect. The griddletop seal sounded like the nozzle of a vaccum cleaner: brief opening allowed a full rush of air into the stove that you could tell the fire really wanted. Looking from outside, the chimney was belching thick clouds of brownish smoke with an acrid "way too hot!" smell. At its peak, a single glowing dustball ember drifted down from the liner's exterior onto the top of the stove, as if to demonstrate there was a real fire danger. Although, my stovetop temps never rose above 400 F during this event, I believe either the creosote burned completely (at least at the base of the flue) and/or the primary thermostat finally warmed up and reduced the airflow enough to extinguish the fire.
Notes: I have a 20' all-vertical run through an internal fireplace chimney with 10x10 clay liner (5' of 6" oval Homesaver ovalflex to 15' of Ventinox 6" round), with a 5' SecureTemp HT insulated chimney topper pipe. The chimney extends 5' from roof. There are no wall braces on the liner -- it just has 2 points of support and rests on clay in areas. House is c.1963. I am considering adding external air intake vent kit run down through chimney (for preheating) to increase overall heating efficiency, so do not want to use poured insulation.
So, with that as an opener, come my questions:
Should this be considered a normal burn-off of creosote?
Wife asks, "If home alone, how do I stop the fire?"
Although internal chimney does not require it, would adding 1/2" insulation blanket around liner act to keep this from happening again?
Notes: I have a 20' all-vertical run through an internal fireplace chimney with 10x10 clay liner (5' of 6" oval Homesaver ovalflex to 15' of Ventinox 6" round), with a 5' SecureTemp HT insulated chimney topper pipe. The chimney extends 5' from roof. There are no wall braces on the liner -- it just has 2 points of support and rests on clay in areas. House is c.1963. I am considering adding external air intake vent kit run down through chimney (for preheating) to increase overall heating efficiency, so do not want to use poured insulation.
So, with that as an opener, come my questions:
Should this be considered a normal burn-off of creosote?
Wife asks, "If home alone, how do I stop the fire?"
Although internal chimney does not require it, would adding 1/2" insulation blanket around liner act to keep this from happening again?