Jotul F600CB- Can't turn it down enough. What is a normal low burn temperature?

[formula_pilot]

I am in the process of learning our new Jotul 600CB Firelight. We had some below freezing evenings, so the past few nights I have been putting a decent load (not packed) of mixed hard / soft wood about an hour before going to bed, to carry it though the night. The problem I have is, whenever I put a decent load in, the temp will climb over 500ºF, even with the air control all the way down, I can not turn the air down enough to keep the temps in the 400’s. Getting too much heat and not long enough burn. In the morning there are not many coals at all, but maybe that will change with full hardwood loads. Is this normal for the new Jotul stoves? I would suspect an air leak, but can not find any. Is my air control faulty or is this normal?

Any other Firelight owners out there?

Thank in advance

Bill

 

[ChillyGator]

Not a Firelight owner but.... it sounds like the Firelight is running just like it should...putting out a lot of heat. The mix with softwood propaby has it burning hot and those temps are about right. If you want it cooler, use less wood. My stove likes to run 600*-625* when cruising with a full load and it would be hard to keep it down in the 400's unless the load was very small.

Hot means clean and with some experience you will find adjustments will become second nature and you'll know how much fuel/air to run it at. Good luck.

 

[sandie]

sounds like he is saying he wants it to burn longer so thinks making it burn lower temp will make it burn longer. How to have it warm enough and last long enough so it goes through the night is the real question I believe. I hve yet to get an all night burn but have not really tried, thought if cold Friday night will load it up and see if I can get up at 7 or so and have enough hot coals to get it up and running again in the AM. Would love for mine to run 24/7 in cold weather. I start at 6 at night and go to bed about 10 so it does not get enough time to heat up much but the room we are in and that can take a few hours to go from 60-68 degrees. Some say they have temps up 10 degrees within and hour or so but not me.

 

[jotulguy]

I would recommend 2 things to help you get an all night burn. First dont not clean out the ash pan...ever. Thats right, i know it doesnt make sense but there is a serious reason why you let it fill up. It acts as an insulator and allows the heat and coals to stay in the stove longer. Second, fill the box will a full load of hard woods. That stove has a huge firebox and is more the able to produce a 12 hour burn time once you become comfortable using it and get a method that works in your setting. One other thing to consider i think is the difference between manufactures idea of burn time and users idea of burn time. Most manufactures consider burn time to be enough coals to restart a fire without a match. that could mean stove top temps of maybe 100 degrees. Most users consider burn time to end when they no longer see the fire.

 

[Backwoods Savage]

Bill and Sandie, a wood stove just will not burn that way. You put wood in and there is no way to control it like you would a gas or oil furnace. That is, you can not load up the stove (even not full) and expect the temperature to stay down. It just don't happen. A wood stove will go up to a certain temperature and hold that temperature for a time and then gradually that temperature will start falling.

The key to overnight burns is how you load the stove and what type of fuel you use. Yes, some depends upon the type of stove but the basics are the same for all. At this time of year we don't worry much about overnight burns and usually put in 2, 3 or 4 splits maximum and not our best wood either. With that, our stove top temperature will usually go up around 500 degrees and will taper off from there. By morning we still have some coals to start the next fire.

When cold air gets here, I like to rake the coals forward. In the bottom rear I like a round or a large split. In the bottom front I like to put a faster burning wood (we use soft maple) which helps get the fire going but won't last like the big one on the bottom rear. For that at present we are using white ash. Oak is great as is most of the really hardest of hardwoods. After this, we simply fill the stove with good wood. When the fire gets going good, that is, the wood gets charred, this is when we start turning down the draft setting. Each stove installation can be different on how you run the draft and you need to experiment. This can be fun with experimenting and keep track of any differences in types of wood and also sizes of the wood. Remember that the smaller the split, the faster and hotter the fire will be. The larger splits or rounds should be saved for night burning when it gets cold. On the draft setting, most will have the draft set quite low when they go to bed and how low you will have to determine yourself. Mine, for instance, gets set to anywhere from .25 to .75 (scale of 1 to 4) after we fill the stove but please bear in mind we have a cat stove so it needs low setting and will burn a long time like this (and burns very cleanly too).

I hope this helps or makes sense to you. If not, please ask more.

I also believe what jotulguy said about the ashes is quite common for what most folks do. Our particular stove has no ash pan and is our first stove like this. I wasn't sure about it but now I love it.

Have fun. Experiment. Keep some records if it helps. Enjoy the heat.

 

[formula_pilot]

Guys, thanks for the replys

Dennis has some well thought out methods for wood placement in the stove, I will give it a try when the real cold weather hits.

I guess I still would like to understand if the draft control on my stove is behaving normally. Is it normal that even when the control is turned down to its lowest setting, the temperature of the stove can continue to climb to 525ºF, mabe even higher if the box was packed? I just wish I could cut the draft down a little more. I can sucessfully maintain lower temperatures in the house by buring smaller fires, but it would be nice to load it up with fuel for a longer burn and not get roasted out. Maybe I am expecting too much from the EPA stove.

Are these stove designed so that you can not fill the firebox for an overnight burn, yet keep the stovetop temps down at 450ºF or so?

 

[Backwoods Savage]

That is true formula_pilot. When you fill that firebox, it is going to get hot. Then it gradually decreases as the wood burns down.

The stoves are designed so that you can not completely shut the air off so even if you close the draft completely, the firebox will still get some air. Not a lot, but some. This is actually good.

Just think, in another month or so you will no doubt be thinking that a 525 degree stove is not hot enough! Then you will want it over 600 and it will feel great.

 

[jotulguy]

Filling the box is adding btu's. So in short no. But that being said you can have some control over how fast it gets up to temp and maybe hold it down a little with practice. I would recommend turning the air down at 350 maybe instead of 450-500. When you turn the air down you will all most always get a small temp rise as the stove slows down so does the draft. Hence more heat in the fire box.

 

[formula_pilot]

I will try turning the control down sooner and letting the ash build up too. I do not mind shoveling out the ash, rather than using the pan, my old stove did not have a pan.

 

[Dexter]

'Have had a firelight CB for 11 years. It took a while to figure it out. I only have access to pine, generally, but I still get an overnight burn (about 8 - 10 hours later, there are coals hot enough to ignite wood the next morning.) Actual flame (from pine) I seldom get more than four or five hours, with pretty good radiant heat for five to seven.

The following uses an inexpensive Home Saver stove thermometer on the right-rear top-corner of the stove...

I agree with some of the posts above: I reduce the air controll sooner -- to about 1/2 across the scallop pattern on the ash lip -- when the temp hits about 250 degrees. (That's about over the fifth indentation from the left, inclusive of the first indentation. At 350 it goes over "indentation #4", and at 400-450, to "indentation #3" (or a tiny bit further open -- its quite touchy). Over 500 degrees, I take it down to indentation 2 1/2. (At about "indentation 2", the primary air is as closed as far as it will get, but at my altitude, I almost never quite shut the control all the way down. With large fires, even using this system, it will occasionally go over 600. That's the nature of the beast. A graph of a typical burn has (in the first two hours) a very steep slope to 500 or so, with a (not as) steep decline to about 375. It cruises there for about another hour and a half, then a long, slow, reduction in temp over several more hours. 'Just the nature of the beast. We love our stove, but it DID take some experimentation.

Regards,

 

[DiscoInferno]

The "problem" with non-cat EPA stoves is that they provide seemingly unlimited secondary air no matter the primary air setting. This helps ensure complete combustion, but it adds enough positive feedback (i.e. heat) that it also burns/gassifies the wood faster then is desired sometimes. I almost always burn both my non-cat stoves on the lowest air setting once they are going good, but a full firebox still means a pretty roaring flame at that setting. So as others suggest, you learn to modulate the heat through wood type, size, and quantity as well as reducing the air as quickly as possible (without smoldering). Larger splits have less surface area, and will burn more slowly, for example. Some even find that the direction of wood in the stove (N/S vs. E/W) makes a difference because of different airflow patterns.

 

[branchburner]

Are these stove designed so that you can not fill the firebox for an overnight burn, yet keep the stovetop temps down at 450ºF or so?

A stove designed to do that is the catalytic Blaze King, with thermostatic control. A very different animal than yours (and mine).

 

[firefighterjake]

I am in the process of learning our new Jotul 600CB Firelight. We had some below freezing evenings, so the past few nights I have been putting a decent load (not packed) of mixed hard / soft wood about an hour before going to bed, to carry it though the night. The problem I have is, whenever I put a decent load in, the temp will climb over 500ºF, even with the air control all the way down, I can not turn the air down enough to keep the temps in the 400’s. This is a common mistake for many folks who are either burning for the first time or who have used a non-EPA stove in the past -- and it's normal. In a car if you need to go slower you use less gas, right and so many folks assume that if you need less heat you reduce the air. In a similar vein of thinking, folks with experience in using non EPA stoves are used to cutting back the air on their older stoves to get a longer burn -- although in the process you also suffocate the fire and cause a smoldering, creosote-clogging chimney mess in time. Closing the air control with a modern EPA stove actually will result in more heat . . . if the wood is seasoned and the temps are right. Why might you ask is this the case? Answer -- you're keeping more heat in the stove and less heat is going up the chimney (which is why after closing the air control or shutting it a good amount you will most likely see the temp on the flue either stay the same or go down slightly while the temp on the stove rises). On top of this, closing the air control is often one of the last steps to achieve secondary combustion -- which is where the magic happens. No, I'm not talking about pulling rabbits out of hats or dancing, prancing magical unicorns -- I'm talking secondary combustion -- aka the Bowels of Hell. This is the reason why your stove is efficient and is able to really put out the heat. So . . . when you start closing the air thinking you are reducing the heat you are in fact often doing just the opposite -- increasing the heat in the firebox. To best control the heat you can do so my controlling what you put in the firebox (i.e. higher BTU wood vs. lower BTU wood, size of the splits (small vs. large) and how much wood you put in the firebox (i.e. half load or stuffed to the gills).. Getting too much heat and not long enough burn. In the morning there are not many coals at all, but maybe that will change with full hardwood loads. Is this normal for the new Jotul stoves? I would suspect an air leak, but can not find any. Is my air control faulty or is this normal? This is normal . . . and not a leak. To get a longer burn and have enough coals in the morning to easily re-start the fire you can make a few changes -- 1) use only hardwoods on this final fire, 2) use larger splits and rounds and 3) load up the firebox. The negative with this . . . if you can call it negative . . . is that your Firelight is designed to really heat up the place . . . if you do all three of my recommendations -- load the firebox up with larger, seasoned, high BTU hardwoods a half hour before you go to bed, get the stove up to temp, turn down the air and achieve a good, sustained secondary burn you should wake up in the morning with some coals . . . but more importantly you will have also kept the house warm all night long and have done so in a clean and efficient manner . . . again . . . depending on how cold it is . . . you could be producing a lot of heat in the home.
Any other Firelight owners out there? Oh yeah, suppose I should come clean . . . I own an Oslo . . . younger brother to the Firelight . . . but a very good heater in its own respect.Thank in advance

Bill

 

[firefighterjake]

I would recommend 2 things to help you get an all night burn. First dont not clean out the ash pan...ever. Thats right, i know it doesnt make sense but there is a serious reason why you let it fill up. It acts as an insulator and allows the heat and coals to stay in the stove longer. Second, fill the box will a full load of hard woods. That stove has a huge firebox and is more the able to produce a 12 hour burn time once you become comfortable using it and get a method that works in your setting. One other thing to consider i think is the difference between manufactures idea of burn time and users idea of burn time. Most manufactures consider burn time to be enough coals to restart a fire without a match. that could mean stove top temps of maybe 100 degrees. Most users consider burn time to end when they no longer see the fire.

Jotulguy makes a few other key points I forgot . . . and will echo here . . .

1) I don't totally agree with his idea of never cleaning out the ash pan . . . and in fact I do so once or twice a week with the Oslo. However, more importantly . . . you don't want to clean out all the ash in your firebox . . . you want a layer of ash and coals an inch or two deep since . . . as mentioned . . . it acts as an insulator and helps keep the coals "live" for longer. When I clean out my ash pan I carefully remove it so that the ash in the firebox stays put . . . after dumping the ash in my bucket outside I return the ash pan an then rake things up . . . again, being careful to leave an inch or two of ash in the firebox.

2) His definition of burn time is spot on . . . as prospective buyers our opinion of what the definition of burn time is may be quite different from whatever the manufacturers believe the definition of burn time is . . . me . . . I'm quite happy when I can go to bed at 9:30 p.m. and wake up at 4:30 a.m. or 5 and have enough coals to easily re-light the fire by simply tossing on some kindling (although my much more patient wife often only uses some small splits to preserve the kindling.)

 

[firefighterjake]

Guys, thanks for the replys

Dennis has some well thought out methods for wood placement in the stove, I will give it a try when the real cold weather hits.

I guess I still would like to understand if the draft control on my stove is behaving normally. Is it normal that even when the control is turned down to its lowest setting, the temperature of the stove can continue to climb to 525ºF, mabe even higher if the box was packed? I just wish I could cut the draft down a little more. I can sucessfully maintain lower temperatures in the house by buring smaller fires, but it would be nice to load it up with fuel for a longer burn and not get roasted out. Maybe I am expecting too much from the EPA stove.

Are these stove designed so that you can not fill the firebox for an overnight burn, yet keep the stovetop temps down at 450ºF or so?

Your air control is normal . . . as I stated in my other post . . . and as others have stated. Closing the air control typically will result in more heat in the woodstove and either no change or a slight drop in the temp of the flue. It's normal . . . and it is a good thing . . . especially when the very cold weather arrives.

As Jotulguy mentioned you can try closing the air a bit earlier . . . and this will help keep temps from spiking very high . . . although the temps you mentioned are not bad at all for a large cast iron stove like the Firelight. This will help keep the stove top temps down a bit . . . using larger splits or rounds can also help. However, the best way to moderate the heat is by controling your fuel load -- how much wood you put in the firebox, size of the splits and type of wood.

Getting a long, low overnight burn can be a challenge with a stove like this . . . getting a long, overnight burn that really puts out the heat should not be an issue . . . getting the house warmed up without getting roasted alive with a stove like this can also be done -- but you will not get the longer burn times . . . getting a long, low overnight burn during this time of year is possible -- but not with a stove like we have -- it is possible with a cat stove.

As Dennis mentioned . . . come winter you'll be wanting to crank out the heat.

 

[Skier76]

We've got a Jotul Castine at our weekend place. Long story short...it cruises along really nicely around 450-500(maybe 525) with a nice full load of wood and the air backed all the way down. That seems to be how the stove runs. Granted, your stove is bigger, but it should run about the same.

 

[sentic]

I've owned a 600 firelight for only a few months. Owned a VC Resolute before upgrading..owned it for 8 years (came with the house). On both stoves if I want an extended burn time I put a really big, whole log clear in the back and build the fire in front of it. Its trickier when the fire is going, obviously, but possible if I let it burn down to good coals.

1) Put a whole log of good hardwood in the back.
2) Put smaller splits in front. Pack it as high as necessary to achieve the temps you want.
3) Adjust air. If I'm going to bed I'll pack the stove and turn the air 3/4's of the way down. The 600 will run 300-400 degrees all night long and in the morning that back log will only be 1/2 way burned down and full of so many coals that restarting for real heat is a snap.
4) During the slightly cooler months (Oct-Nov) in Michigan, a slow burning log like that will still be good coals 15 hours later. Its a SLOW burn though because we didn't need a lot of heat and then you need to keep track of the creosoting problem.

I love this stove. Well built, and really cranks the heat.

 

[santiago]

eldorado,
Is your 600 a non cat?

 

[Dexter]

From reading posts of different firelight cb owners, it appears that there is a wide variation in drafts. Our's is somewhere in the middle: a good, but not a "whistling" draw when there's no fire.

I burn North/South only, and usually have nothing but extremely dry pine. However, if I shut down my primary air to the lowest setting (too soon), after the temp spike, the fire will subside well ahead of the fuel being spent. Note, however that I'm at 5300 feet; I'm sure that makes a difference. I don't have to open the air control much, though, before there's enough air to burn the wood down to coals.

In our circumstances, you can pack a 200 degree firebox full of pine and shut it down to less than 1/2 air at 275 degrees. At 350, it can go almost, but not quite, down to minimum primary air. Visible flame almost never continues after 5 hours (4 hours is typical). But coals hot enough to easily relight new fuel exist for 8 -- and sometimes, up to 10 -- hours. BTW, in our case, an all blue, "northern lights" secondary burn tends to be a little dirty for us. (it leaves a dry dust on the glass, but it'll wipe off with dry tissue.) Mixing the smallest additional primary air "yellows" the fire a little, but keeps it spotlessly clean, and does not seem to shorten the endurance of the hot coals.

Regards,

 

[summit]

one thing that'll kill ya on burntime is softwood mixing... I use it alot on shoulder seasons, but for burn time (much like in the adult film industry), you need big hard wood. The F600 seems to burn full bore when you throw alot of little limbs and small splits in, but to eek it out more, you need some big splits and +/- 6" dia rounds to run the full 12hrs on her..