Questions about my 30 NC

I have similar experience to what Pen said. Except my secondaries kick in around 400-500 without any fuss with good wood. Most of the stuff I have is pretty good. My stove frequently runs 7-800 on secondaries alone.

I have a different size and brand of stove, but it works basically the same way as yours. I see secondary burn throughout the burn cycle, but sometimes it is harder to notice than others. Once the stove gets hot and the fire is going strongly I see yellow 'primary' burn starting at the wood. Generally where this flame reaches the secondary burn tubes I see secondary burn mixed in with the primary. I differentiate between the two because what I think is secondary burn shoots down and out from the secondary burn tubes instead of shooting up from the wood like normal primary burn.

In my stove, I can reduce the primary air when I get strong yellow flames from the wood. If the wood is hot enough to out-gas, turning down the primary air will increase the secondary flame. As I just said, strong primary flames usually mean there is some secondary flame although the secondary might be hard to notice. At other times, when I guess the wood isn't hot enough, the secondary flame will die out as the primary flame dies back. In my stove I usually have to maintain some primary flames in order to maintain good secondaries. A good burn for me means a modest amount of primary flame (maybe 1/4 of the width of the stove has yellow primary flame) and secondaries over most of the stove (at least 3/4 of the width of the stove has consistent secondaries). this means the primary air is open about 1/4 or so, but it varies.

And you need to make the distinction between a "cold load," when the stove and flue are cold or barely warm, and a "hot re-load," where the stove and flue are heated. The stove behaves very differently in these situations.

If you can build a fast, hot fire in a cold stove, you'll get secondary combustion, both at the jets, and around the firebox. But don't be surprised if you can't get it until you've figured out how to heat the stove up fast enough. Otherwise, most of your first load is sacrificed to heat up the stove and flue/liner, and to get a red coal bed in the bottom of the firebox.

Subsequent loads should be put in while you've still got enough heat in the red coals to get the wood going fast and up to the range where secondary combustion can occur. If you wait too long, you'll be in "cold load" mode again, and I found that was a great way to waste wood.

If you've got red coals lying all over, you can usually wait 5-10 minutes after adding a fresh load, and then gradually turn the air down. If you've got a good set up and good wood, you might be able to slide the air control fully in, but you might also cool off the fire too much that way and lose secondary combustion. You have to gauge it by what you see in the firebox, and since you're new to this, it will take some learning.

I can't speak for others, but it's rare that I ever have the air control fully closed.

What none of us has actually stated clearly is that secondary burn requires excess wood gases and particles to be released from the wood, and this stops once the wood gets to the coal stage. So, once you get to the coal stage don't expect much if any secondary combustion.