Secondary burners

[Kevin Dolan]

A question about secondary burners. I have a jotul 400 and when I am burning a small fire the splits are not up to the tubes and so once it gets going I don't always see the secondaries shooting the blue flames out. My question is do you have to see these blue flames out the secondaries to have them working? With the primary air intake turned down to around a quarter of the way and no apparent secondary action, is the the fire just heating the cast box and radiating that out to the room or is a lot of my heat going up the chimney? From my questions you will see that I do not really understand the air flow through my stove.
When I have a larger fire 4-5 decent splits, I see lots of secondary activity and think this is because the wood is closer to the secondaries but not sure if this is the cause. Any comments appreciated.
Kevin

 

[DianeB]

my secondaries are not generally blue. I can get secondaries going with just a couple of splits. I watch the thermometer and when it hits 400, I start turning down the air lever. By 400 I see secondaries and that is when I start to turn down The secondaries usually burn even if I turn air down slighly below 1/2 air. If I get to 1/4 air, the secondaries usually go out. I have not built a big fire yet as not that cold. I think when colder, will let the stove hit 500-600 before turning it down and think I will be able to get 5 good size pieces if not more in the stove. I am new to the EPA stove having burnt in an old Fisher for many years

 

[pen]

With a smaller fire, if the primary air you are providing the stove by means of your air control is all that the fire needs, then you won't see much secondary action as there isn't much unburnt fuel making it up to the air that those secondary tubes are providing.

For me, getting true blue flames out of the secondaries usually happens as my fire is waning, later in the burn cycle.

Go check the chimney, if you aren't billowing smoke around the neighborhood, all is good.

 

[Huntindog1]

Kevin, was that on a cold start or load on coals?

 

[ailanthus]

I believe you do have to see the blue (at least mine are blue) flames at the secondaries for them to be working. With a small fire, if I try to cut back the primary air too much even if the stove is up to ~400, there may not be enough flames from the primary air to ignite the secondaries. In that situation, secondaries can ignite intermittently, but that tells me that in between, there are some unburned gases. As you said, it's much easier to get the secondaries rolling on a full load, and even moreso when burning 24/7.

 

[stoveguy2esw]

they really do not have to be blue, usually you will have blue "roots" to the flames but having secondaries which are yellow to orange doesnt mean you arent burning clean.

as for small fires it may not be as active due to less fuel being released by the primary fire as well as simply less heat buildup under the refractories this heat is necessary to relight the fuel as it reaches the secondary zone in the stove, kinda like the heat needed to be built up to get a catalyst to go active and start reburning.

now just because you do not see flames it doesnt mean you are burning dirty, may just be getting burned away in small patches which do not show an active flame.


as said above , check the exhaust leaving the top of the flue, if you arent smoking you are ok.

 

[binko]

Unfortunately in non-cat stoves, if you do not see secondaries you are probably sending smoke up the chimney-especially in the early part of the burn cycle.
This is why I went back to a cat stove. It's hard to run a non-cat stove at low temps and still re-burn all of the smoke. You need dry seasoned wood for all stoves, but it's far more important in the non-cats.

 

[mellow]

Dry seasoned wood is just as important for a cat stove, thermal shock from moisture will kill a cat quickly.

I agree that a cat can run at lower temps more efficiently, but you can can still do it with a tube stove if you are using dry wood.

 

[Kevin Dolan]

Kevin, was that on a cold start or load on coals?

that was on a cold start

 

[Huntindog1]

Loading on a bed of coals means the stove can be already pretty hot. If the coals are pretty hot the stove can be up to temps pretty quick and then when you shut your air down you will see the secondaries light off pretty easy.

 

[corey21]

During my last too fires i found out that if wait till 400 stove top then close the air half way the secondary system really takes off Then at 500 i can close the air to barely open and it will cruise and temps go up a little more. .

Basically you need to get the stove up to 400 stove top before it will start burning gases.

 

[KaptJaq]

When I burn full, hot fires my secondaries are blue jets of flame coming from the holes in the secondary burn tubes. When I have a small hot fire or later in the burn of a large fire the secondaries look more like the northern lights. Soft yellow, orange, and blue flames above but not actually touching the wood/coals and only occasionally touching the the secondary burn tubes.

In either case there is no visible smoke coming from the flue.

KaptJaq