We got our new GM60 up and running on Saturday, just in time for the cold snap. We’ve been taking it slow and learning to build a good fire, and mostly burning mimosa that’s at 14-17% moisture but kind of junk as it’s already breaking down and burning quickly. Our main concern with this stove was that we might have a hard time getting a good draft, but even with a 13’ chimney it was probably too strong. We figured this was partially due to the sub-zero temps outside and were looking forward to yesterday’s rise to the mid-30’s so we could compare.
I had the stove offline during the day so I could check out the chimney (it's clean!) and install a flue thermometer. I started a fire late afternoon, same as I had been doing, ending up with three splits of mimosa lasting about three hours. The draft was still great, with the smoke rolling up past the baffle and out the flue on a cold start with the door cracked. With a bed of good coals pushed to the front of the stove and a STT of 300, I added a big split of what we think is oak, a split of holly, and a piece of mimosa on top. We haven’t yet built enough trust with this thing to pack the box full, but we were hoping for a better overnight with the oak.
In a matter of minutes, I had a raging inferno. I’m guessing it was five minutes. I had engaged the cat and cut the air down a little at a time, but meanwhile the fire kept growing, so I quickly cut it to almost closed. Within ten minutes, the air control was completely closed, I had rolling orange flames filling the box, purple and orange secondaries exploding against the glass and rolling all directions back into the firebox, and bright orange rocket blasts coming from the holes in the riser. STT was 630 within maybe 15 minutes. I was too panicked to note the flue and cat temps, but I think they were both near the middle of the normal range. The secondaries were so out of control that it seemed that they were trying to blast out of the fire box, like the primary and secondary flames were competing for space because there wasn’t enough rom in there to contain it all. All told, it was probably 30 minutes of rage (stove) and panic (me).
We finally decided to “dump the gas” by opening the bypass and opening up the air control a bit. It worked. After that we were able to get it under control, but the flames were bigger than I would like and the stove hotter. I barely had the air control open and had big orange flames along with big billowing secondaries, but if I cut the air completely, every flame would completely die out in a matter of seconds. This doesn't seem normal.
I started a fire this morning and had no trouble, likely because I went back to three splits of junk mimosa, but it still only lasts three hours until the coals at dying and temp is back to around 275-300. I cut some kindling out of the oak from last night’s fire and threw it on to see what would happen, and the smoke coming from it was black. Thankfully, I had only put in kindling and not the full logs, so I let it burn out but the smoke stayed black to the end. Any advice on what could be causing the black smoke? Contaminants seem unlikely as this would have been a tree that my husband cut down himself and split. I realized I had never tested moisture on the “oak” (?) or the holly, so I did, and got 8% and 7%.
So, obviously I’m not going to burn the 8% maybe oak, with black smoke coming out of it, or the 7% holly. Obviously I’m going to measure my draft very soon so I can figure out how much that’s contributing. But in the meantime, what else do I need to do differently so I can get a burn longer than three hours without burning my house down? I feel like the answer is going to be that I need to load the fire box with more splits so there's less air, and install the damper I bought, but having only been burning for six days, I'm still learning what's normal and would love to hear your thoughts... I was already nervous about filling the box and last night did not help.
I had the stove offline during the day so I could check out the chimney (it's clean!) and install a flue thermometer. I started a fire late afternoon, same as I had been doing, ending up with three splits of mimosa lasting about three hours. The draft was still great, with the smoke rolling up past the baffle and out the flue on a cold start with the door cracked. With a bed of good coals pushed to the front of the stove and a STT of 300, I added a big split of what we think is oak, a split of holly, and a piece of mimosa on top. We haven’t yet built enough trust with this thing to pack the box full, but we were hoping for a better overnight with the oak.
In a matter of minutes, I had a raging inferno. I’m guessing it was five minutes. I had engaged the cat and cut the air down a little at a time, but meanwhile the fire kept growing, so I quickly cut it to almost closed. Within ten minutes, the air control was completely closed, I had rolling orange flames filling the box, purple and orange secondaries exploding against the glass and rolling all directions back into the firebox, and bright orange rocket blasts coming from the holes in the riser. STT was 630 within maybe 15 minutes. I was too panicked to note the flue and cat temps, but I think they were both near the middle of the normal range. The secondaries were so out of control that it seemed that they were trying to blast out of the fire box, like the primary and secondary flames were competing for space because there wasn’t enough rom in there to contain it all. All told, it was probably 30 minutes of rage (stove) and panic (me).
We finally decided to “dump the gas” by opening the bypass and opening up the air control a bit. It worked. After that we were able to get it under control, but the flames were bigger than I would like and the stove hotter. I barely had the air control open and had big orange flames along with big billowing secondaries, but if I cut the air completely, every flame would completely die out in a matter of seconds. This doesn't seem normal.
I started a fire this morning and had no trouble, likely because I went back to three splits of junk mimosa, but it still only lasts three hours until the coals at dying and temp is back to around 275-300. I cut some kindling out of the oak from last night’s fire and threw it on to see what would happen, and the smoke coming from it was black. Thankfully, I had only put in kindling and not the full logs, so I let it burn out but the smoke stayed black to the end. Any advice on what could be causing the black smoke? Contaminants seem unlikely as this would have been a tree that my husband cut down himself and split. I realized I had never tested moisture on the “oak” (?) or the holly, so I did, and got 8% and 7%.
So, obviously I’m not going to burn the 8% maybe oak, with black smoke coming out of it, or the 7% holly. Obviously I’m going to measure my draft very soon so I can figure out how much that’s contributing. But in the meantime, what else do I need to do differently so I can get a burn longer than three hours without burning my house down? I feel like the answer is going to be that I need to load the fire box with more splits so there's less air, and install the damper I bought, but having only been burning for six days, I'm still learning what's normal and would love to hear your thoughts... I was already nervous about filling the box and last night did not help.
