Lesson learned. Shoulder season burning is tricky. Out of cord wood, burning oak pallet wood. Night is relatively mild, upper 30s, but windy. I start up my VC 1450 NC from scratch. The pallet wood burns fast and I'm at 450 before I know it. I've got other stuff to do, so I stuff the box with more oak pallet wood. Knowing I've got to leave it for about 20 minutes, I engage the secondary burn so it won't go nuke on me. When I get back to the stove, the glass is dark and it looks starved for air. I'm surprised. When I open the flue I'm even more surprised when the stove explodes in a significant concussive blast that sends flames out the flue collar. I think "holy ##$!" that isn't good! Seconds later my gut turns as I hear a nasty crackling in my connector pipe (that feeds my OTW 23' stainless class A chimney), and my stove is roaring nuclear. Then smoke is billowing out the top of the connector at the 90, and seems like its on its way to melting down. The house is filling with smoke, alarms are screaming.
A box of baking soda helps put the fire down, windows opened, unpleasant situation is eventually resolved...
So it wasn't a chimney fire, the pipes are all clean. My theory is a perfect storm of weather conditions, poor fuel usage, and operator error. I engaged the secondary way too soon. The fast burning pallet wood continued to produce large amounts of combustible gas in the box. The low draft set up on the milder night, and possible wind intrusion down the chimney reversed my draft. By the time I opened the flue, the two air masses collided with the explosion and the draft was gone, and my house was now the chimney.
Here's the changes I'm considering to my set up: Adding 1' to my chimney. Now it barely meets the 24" rule above the peak. Its close. Its probably 21" above the peak at 14' away. And adding a Vacu Stack or similar cap to replace my basic Air Jet rain cap, and add wind protection. And operate a bit better too.
Thoughts welcome. Has this happened to anyone else?
A box of baking soda helps put the fire down, windows opened, unpleasant situation is eventually resolved...
So it wasn't a chimney fire, the pipes are all clean. My theory is a perfect storm of weather conditions, poor fuel usage, and operator error. I engaged the secondary way too soon. The fast burning pallet wood continued to produce large amounts of combustible gas in the box. The low draft set up on the milder night, and possible wind intrusion down the chimney reversed my draft. By the time I opened the flue, the two air masses collided with the explosion and the draft was gone, and my house was now the chimney.
Here's the changes I'm considering to my set up: Adding 1' to my chimney. Now it barely meets the 24" rule above the peak. Its close. Its probably 21" above the peak at 14' away. And adding a Vacu Stack or similar cap to replace my basic Air Jet rain cap, and add wind protection. And operate a bit better too.
Thoughts welcome. Has this happened to anyone else?
