Unless you lay a split piece directly over the slot with very few coals left I’ve found it impossible to plug it. Been running for about a month now, you’ll also find you get very little ash as well.
Was down to 8 one morning a week or so back with 6-8” of snow, ran my sidewalk as well to melt the snow off, my 400 barely noticed the increase in load. With the old one I had built every time you walked by you could count on throwing in a few more pieces to keep up with the sidewalk and that wasn’t heating the shop as well. Most of last winter if I wanted to melt snow I’d start the waste oil boiler in the shop as the old wood boiler just ate the wood up.
I’ve also found unless you start to cover up the primary air slots there is no such thing as too much of a coal bed.
When the laws were first past a lot of people scrambled to find conventional’s as they were afraid of all the headaches associated with gassers, like having to keep the perfect coal bed as in not too much or too little, needing bone dry wood, plugging the slot up, bridging in the firebox, etc. I’ve only run the G400 but from what I’ve seen the G series makes all those concerns non issues.
I’m going out in the woods once a day and cutting pole trees up, some are still standing and some are down. The ash I cut yesterday was 23%, the wild cherry was 18% (both off the stump) and the tulip poplar was 28%, mix em together and it’s running just fine.