I had just finished one stack of wook and started another...and now the stove wasn't burning worth 2 cents. I figured it was a row of bad wood (although we season very carefully). When the problem persisted, I thought & thought... . About the time the stove started burning badly, it had been extremely windy (gusts to 70.) Could it be the clean-out plug on the Tee at the bottom of the (double wall insulated) chimney? I opened the bottom chase cover, very carefully, as we had a fire struggling along at the time. Sure enough the cleanout plug had blown off. '
Interestingly, there was plenty of cool air sucking into the opening and the entire cleanout area was cool to the touch (Under normal conditions, the plug gets hot.) Also, there was NO WAY the wind could have blown the plug out. It's fit is simply too tight. A mystery!
My guess is that the wind, which was very gusty that day, as well a being strong, somehow drew enough hot unburnt smoke/gas into the chimney, and then air was drawn in (or maybe blown in from the top), and the charge ignited in a "back puff". We didn't hear anything that day, but we did smell an uncharacteristic whiff of smoke that morning.
Anyway, I slid and tapped the plug back into place and the fire was instantly cured. I burned a couple of very hot fires while we were standing by with extinguishers and aluminum foil balls (to plug the air intake) in case of a runaway/chimney fire. All is well, but I found the whole issue to be disconcerting. I think I'm going to mount a coil spring on the chase-bottom cover door to prevent a blow out in the future. It will press on the plug handle only, which remains cool to the touch during a 600 degree fire (although the plug intself gets pretty hot). This is the first time in 11 years that this has happened.
Interestingly, there was plenty of cool air sucking into the opening and the entire cleanout area was cool to the touch (Under normal conditions, the plug gets hot.) Also, there was NO WAY the wind could have blown the plug out. It's fit is simply too tight. A mystery!
My guess is that the wind, which was very gusty that day, as well a being strong, somehow drew enough hot unburnt smoke/gas into the chimney, and then air was drawn in (or maybe blown in from the top), and the charge ignited in a "back puff". We didn't hear anything that day, but we did smell an uncharacteristic whiff of smoke that morning.
Anyway, I slid and tapped the plug back into place and the fire was instantly cured. I burned a couple of very hot fires while we were standing by with extinguishers and aluminum foil balls (to plug the air intake) in case of a runaway/chimney fire. All is well, but I found the whole issue to be disconcerting. I think I'm going to mount a coil spring on the chase-bottom cover door to prevent a blow out in the future. It will press on the plug handle only, which remains cool to the touch during a 600 degree fire (although the plug intself gets pretty hot). This is the first time in 11 years that this has happened.