Having trouble getting up to temp, advice, please!

[pr0vidence]

Greets all.

Been burning when it's cool for a few weeks now, trying different things, learning how the stove works. One ongoing issue I seem to be having is getting the stove up to it's operating temperature. I have a brand new Rainier. Here is what I have been doing:

I start with some cut up slats off a pallet, broken into smaller bits to get things going, light those up, once they are burning and the temp gauge starts to move, I load in a few smaller splits and close the door. Within a few minutes those catch and the temp lifts off into the 200-250 area. Once that gets going good I take some larger splits and stuff 'em in there. Close the door and let her go at full air for 15 minutes or so, once the temp gets up around 400 degrees I start backing down the air a little. First to 3/4, no noticeable change in the fire, however the temp slowly rises a little more to about 450. Cut back the air to 1/2, flames still stay about the same, temp climbs to around 500. This is where I get stuck. This stove should hover around 600-650 when it's in it's happy state, but no matter what I do, it won't climb past 500, I've gotten it as high as 525 once, for about 15 minutes and it sank right back down to 500. Clearly I am doing something wrong but I don't know what, I've used softer woods and harder woods, I've tried a few splits and I've loaded it to the very brim. I have tried leaving it at full air, but at full air it gets up to about 400 degrees and won't budge from there, it continues to climb when I knock the air back a bit.

Another problem (that may be related) is that I can't seem to convince a decent secondary burn to maintain for very long. When it gets up to about 500 degrees, if I cut the air pretty far down, say 1/2 inch in from all the way down, a secondary burn will kick in, but only maintain for maybe 15 minutes before it gets smaller and smaller and smaller until it finally goes out and the stove begins to cool, and the wood just smolders until I give it more air, at which point flames appear again.

Even at 500 degrees this stove is working wonders for heating our home and we love it. I am, however, just learning how to operate it and want it to be as efficient as possible. I am hoping the experts here will have some good advice for me, and some insight as to what I am doing wrong.

One thing I have noticed was that one of the fire bricks that are lining the top of the stove is broken, I don't know if it was broken when we got it or not. I know it should be replaced, but how much does a broken fire brick affect the stove? No pieces of the brick are missing, it's just split down the middle. If I need to I'll get a replacement, otherwise, if it's no big deal, I'll get one in the spring.

Thanks in advance for any insight!

-pr0v

 

[jpl1nh]

500 sounds pretty good to me but I'm not familiar with your stove. While it is getting cooler outside, it isn't cold yet and another 20 - 30 degrees colder will up your draft a bit and help it burn hotter. I'm assuming your wood is really nicely seasoned and dry. A bit of extra moisture makes a huge difference as well.

 

[begreen]

You're not at a bad operating temp. How is the wood? Is it nice and dry? What size are the splits? Have you tried smaller pieces?

If all that checks out well, then the next thing is to look at the baffle created by the firebricks. This baffle needs to be solid with all the firebricks seated correctly in their channels. If the fire has an opportunity to go behind or through the baffle and straight out the flue, it will. There should be no gaps between the bricks.

 

[Ithaca]

I'm new to this too but let me share something I've learned.

Flame color. Bright flames are hotter than orange/blue flames. Set your air control at the lowest setting that still supports bright/white primary flames through out the firebox. Set it too low and the flames will turn orange or will go out in spots. Set it too high and you have excess air which cools the firebox.

You may have to go through 2 or 3 cycles of wood to get it up to temp. Put the next load in while the first is still a large bed of coals and before the stove has cooled. You should see your temps rise. And remember to use smaller splits. 1 Large log will burn slower and not as hot as 3 smaller ones. Also make sure air can flow throughout the firebox. I have found that it helps to leave a channel in front of the doghouse to the back of the stove for air to travel. In the beginning I packed the wood up to the doghouse and got longer burns but not as hot as the fire took time to get to the wood in back of the stove.

Good luck!

 

[pr0vidence]

Thanks for the replies. The wood is all very dry the tree was taken down 1.5 years ago, cut into 16" rounds before last winter, split early this spring, and stacked in a sunny spot all summer. I don't have a moisture meter, but that should be pretty dry.

BeGreen, the broken brick that I mentioned is one of the ones along the top, there are no other noticeable gaps or spaces along the top. I suppose the bricks could technically be pushed a LITTLE closer together.....a small fraction of an inch. The next time the stove is cold I'll reach in there and try to get them tighter against each other, however I do not notice any flames sneaking up between the spaces.

Finally, thanks for the advice about the color of the flames. I will keep that in mind when I am adjusting the air control. I did notice the fire does a bit better when there's at least an inch or two of airspace between the "doghouse" and the closest log, than where the log is right up against it. Makes a lot of sense.

 

[begreen]

Are you loading N/S or E/W in the stove?

 

[mranum]

I'm new to this too but let me share something I've learned.

Flame color. Bright flames are hotter than orange/blue flames. Set your air control at the lowest setting that still supports bright/white primary flames through out the firebox. Set it too low and the flames will turn orange or will go out in spots. Set it too high and you have excess air which cools the firebox.

Not sure but I think you have that backwards. The hotter a flame is the more blue it gets, when my secondary tubes turn red there isn't a yellow flame anywhere in the box, its always blue. The more air you put into the box the hotter it will run as you are adding more oxygen to the fire.


(broken link removed)

The typical, bright, yellowish-orange upper part of a flame is due to the heating of unburned carbon particles.

The temperature of the fire and the material being burned are the factors that determine the color of the flame. The various colors of flames in a wood fire are due to the different substances in the flames.

The strong orange color of most wood flames results when sodium contained in the wood is heated.

The temperature of wood flames is lower than that of candle flames, which colors the wood flames orange, not yellow. If, however, some of the carbon particles in the fire are very hot, the color will be yellow. The product of the burnt carbon, when it has cooled, is black soot.

Since fire needs oxygen to burn, and since the bottom of a candle flame does not get much oxygen, it is the hottest spot in the flame and is blue in color.

The flame cools and changes color as it moves away from the source of the flame, because it is exposed to more oxygen. The temperature change causes the color of the flame to change from blue, at the hottest, lower portion of the flame, to the typical, bright, yellowish-orange or bright orange color with which most people are familiar with. Which shade of orange is seen at the upper portion of the flame, where the flame is the coolest, depends upon the material being burned.

 

[stanb999]

I'm new to this too but let me share something I've learned.

Flame color. Bright flames are hotter than orange/blue flames. Set your air control at the lowest setting that still supports bright/white primary flames through out the firebox. Set it too low and the flames will turn orange or will go out in spots. Set it too high and you have excess air which cools the firebox.

Not sure but I think you have that backwards. The hotter a flame is the more blue it gets, when my secondary tubes turn red there isn't a yellow flame anywhere in the box, its always blue. The more air you put into the box the hotter it will run as you are adding more oxygen to the fire.


(broken link removed)

The typical, bright, yellowish-orange upper part of a flame is due to the heating of unburned carbon particles.

The temperature of the fire and the material being burned are the factors that determine the color of the flame. The various colors of flames in a wood fire are due to the different substances in the flames.

The strong orange color of most wood flames results when sodium contained in the wood is heated.

The temperature of wood flames is lower than that of candle flames, which colors the wood flames orange, not yellow. If, however, some of the carbon particles in the fire are very hot, the color will be yellow. The product of the burnt carbon, when it has cooled, is black soot.

Since fire needs oxygen to burn, and since the bottom of a candle flame does not get much oxygen, it is the hottest spot in the flame and is blue in color.

The flame cools and changes color as it moves away from the source of the flame, because it is exposed to more oxygen. The temperature change causes the color of the flame to change from blue, at the hottest, lower portion of the flame, to the typical, bright, yellowish-orange or bright orange color with which most people are familiar with. Which shade of orange is seen at the upper portion of the flame, where the flame is the coolest, depends upon the material being burned.

That is a child explanation of what is taking place..... Or not exactly.

In burning wood or anything for that matter you create oxygen starved conditions with the most volitile processes taking place first.

Stage one. carbon conversion this burns clear It produces a tremendous amount of heat. But starves the remaining gasses of oxygen. This is why the match turns black. Due to the fact that no oxygen remains you get a flame that seems to not be attached.

In the above process the gasses are driven off the underlying wood. The main product of this combustion is H2 20% or so. But you also get 10% or so of CO and various other tars, oils, minerals.

The first most volatile compound in the mix is Hydrogen. It burns with a blue flame. Thus starving the other gasses of oxygen.
The next gas to burn is the CO this burns white. This also starves the remaining gasses of oxygen.
The next to burn are the Sodium gasses. They burn yellow.
Finally the tars burn orange,green,red,purple and so forth.


So with all this said, The hottest part of the fire is the direct carbon conversion with no flame present.

 

[Backwoods Savage]

Providence, you actually answered part of your question in your own post. You stated that when you, "Cut back the air to 1/2, flames still stay about the same, temp climbs to around 500." There is one big key to this equation. If the draft is left open the heat goes up the chimney. When you begin closing the draft you will get more heat from the stove.

For example, on the "slow to heat up soapstone stoves," that people talk about you will find they heat up much faster (from a cold state we're talking here) if you close the draft part way. Leaving the draft open and getting a roaring fire takes a long time to heat all that metal and soapstone. But by closing the draft partway, the heat stays in the stove instead of going up the chimney.

 

[branchburner]

If the draft is left open the heat goes up the chimney. When you begin closing the draft you will get more heat from the stove.
For example, on the "slow to heat up soapstone stoves," that people talk about you will find they heat up much faster (from a cold state we're talking here) if you close the draft part way. Leaving the draft open and getting a roaring fire takes a long time to heat all that metal and soapstone. But by closing the draft partway, the heat stays in the stove instead of going up the chimney.

That's why I find it important that my startup fires (or quick shoulder fires) are made with very small, very dry wood:
I can shut the air back further, and sooner, and still get a pretty clean and hot burn without losing all that heat. Anyone having trouble getting to temp, I suggest hold off a little longer on adding the bigger splits, and make sure your smaller splits are truly dry.

 

[pr0vidence]

BeGreen: I am loading it in an EW fashion.

I realize that cutting down the air helps the stove warm up, but if I cut it down too much the fire suffers and just kind of peters out. I feel like I am wasting a lot of fuel this way. For example, last night around midnight I packed the stove chock full of hardwood, got it ripping, and pulled the air down to almost nothing (almost nothing being as close to the lowest setting I could get it while maintaining flame, about 1/2 inch pushed in from all the way out), by 7am this morning the stove was stone cold. Not even some burning embers on the bottom that could be used to re-ignite.

Perhaps I just need more practice

 

[SlyFerret]

It may not be the cause of the issue that you're having, but I feel that I should probably mention it.

When I first got my Englander 30-NC, I had a little trouble getting the stove up to temp and maintaining a stable secondary. I came to realize (after my first few fires) that the baffle boards in the top of my stove were shifted to the side and not sitting flat. This caused the air circulation inside of the stove to change quite a bit, and made the secondary combustion system not ignite properly. The smoke was exiting out the top of the firebox along the right sidewall instead of having to travel back across all of the tubes to exit across the front.

Double check to make sure that your baffles are setting properly in the top of your stove.

-SF

 

[Ithaca]

The hottest region of a flame and the type of flame that creates the most heat radiation are 2 different questions.

An oxygen starved (smoldering) flame will not be as 'bright' as one with ample or excess oxygen.



The temperature of flames with carbon particles emitting light can be assessed by their color:

* Red

o Just visible: 525 °C (977 °F)
o Dull: 700 °C (1290 °F)
o Cherry, dull: 800 °C (1470 °F)
o Cherry, full: 900 °C (1650 °F)
o Cherry, clear: 1000 °C (1830 °F)

* Orange

o Deep: 1100 °C (2010 °F)
o Clear: 1200 °C (2190 °F)

* White

o Whitish: 1300 °C (2370 °F)
o Bright: 1400 °C (2550 °F)
o Dazzling: 1500 °C (2730 °F)

 

[begreen]

Pr0, try this. When reloading the stove, try laying down a couple thin splits, N/S with say a 6" gap between them. Use those two splits as a bed on which to lay your E/W splits. That should get a bit more air under the bulk of the wood and may help it burn more completely. Also, maybe try not closing the air all the way for a night. Try closing it 75% and see how it works.

 

[bokehman]

Not even some burning embers on the bottom that could be used to re-ignite.

To me it sounds as though you aren't putting enough fuel in. If you are not putting enough fuel your secondary will not sustain itself and you will not have coals in the morning. Weigh your wood before you put it in the stove so we know how much you are putting in. If you've got the Avalon you should be able to fit around 35 lb of hardwood (150,000 BTU's) in it.