Need advice for sustained secondary burn in Lopi insert

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NELopiGuy

New Member
Oct 29, 2023
3
Massachusetts
Background:
I got a new Lopi large wood insert early last spring. We used it for about 5 weeks, and have just restarted use this fall. I've tried really hard to figure out how to get the secondary burn that I see in so many videos (like I'm looking at a gas burner from below), but just can't get this right.
  • Outside temps are in the 40-50s. (But in the spring were in the 30's.)
  • Wood is hardwood and very dry--16% or less when split and measured at the center. I've even purchased kiln-dried bundles, but they didn't measure any less moisture than my seasoned wood.
My Process:
I build a flame up until I have a few pieces of wood going strong. I close the top baffle and 10 min later I will push the primary air valve closed (or 90% closed--have tried both). The flame moves up to the top, as expected, achieving the desired secondary burn. Down on the logs themselves a small flame will remain, but soon it goes out. And then, within 10 minutes, all the flames are out. The only way to get anything that looks like a secondary burn is to keep the primary air open closer to 50-60%, so the logs are flaming. But I don't think that will give me a full overnight burn...

What am I doing wrong?
- Insufficient draft length?
- Add more burning wood before attempting?
- Other?

Thanks! This thing is driving me crazy!
 
Load it clear full and light a top down fire. Start closing down primarily air in increments. You need the primary flames to create the heat for the secondary combustion. Have two air controls is something I’ve never used but I’d just find a decent setting on the secondary and never change it. Most stoves do not control the secondary air.

Burn is cycles load it ass full as you need to for heat then left it burn down to hot coals and and relaod a full load. Just my thoughts.
 
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How tall is the liner on the insert? Does the chimney top meet the 10-3-2 requirement?
 
Burn is cycles load it ass full as you need to for heat then left it burn down to hot coals and and relaod a full load. Just my thoughts.

My non cat EPA stove's manuals says to do exactly that. It starts best with a full or nearly full load. I can do partial loads after the first full load has burnt to coals if I want to maintain a lower heat output. Or use wood with fewer BTUs. I think having wood relatively near the secondary burn tubes helps get it going. Top down is the best way to start the fire in my experience. I leave a gap between splits for a couple twisted newspaper sheets and lay fine kindling on top. Being near the burn tubes helps those burn too.
 
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Thanks everyone. I recall being told that my chimney insert was going to be long enough, but not with a wide margin. Probably around 13-15'. The retailer suggested I buy a $600 extension last week when I raised an issue I had with backdraft after the fire had gone out (but was still smoldering slightly, meaning carbon monoxide was flushed back into the house!).

I've always treated this like a regular fireplace, throwing in a few logs at a time. I guess I needed to really fill it up...I tried that last night and was able to see the secondary burn sustain for quite a while.
 
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On a related note then, could fully loading it make it too hot? As an insert, I don't have a way to monitor the flue temperature. I have an infrared thermometer, but it's intimidating to open the door on a fully loaded, secondary burning box!
 
On a related note then, could fully loading it make it too hot? As an insert, I don't have a way to monitor the flue temperature. I have an infrared thermometer, but it's intimidating to open the door on a fully loaded, secondary burning box!
Why on earth would you open the loading door on a full load?
 
On a related note then, could fully loading it make it too hot? As an insert, I don't have a way to monitor the flue temperature. I have an infrared thermometer, but it's intimidating to open the door on a fully loaded, secondary burning box!

Every stove and install is different. With my Flame Monaco EPA zero clearance fireplace with a 32' flue, I can get it too hot only if I load with a lot of smaller dry splits on top of a big bed of coals. Don't do that- let the coals burn down a good ways. The stove will cycle over the day as you load it and let it burn down, but unless your house is really poorly insulated of drafty the temp inside will be fairly even.

I don't open the door except to load more wood.
 
Thanks everyone. I recall being told that my chimney insert was going to be long enough, but not with a wide margin. Probably around 13-15'. The retailer suggested I buy a $600 extension last week when I raised an issue
That's on the short side. Adding a few feet to the chimney could be good insurance as well as helping the stove to perform better.