How hot is hot?

[jadm]

In another thread on creosote and helping prevent it, BG commented on the need to burn one hot fire a day to minimize creosote build up.

I want a number..How hot is hot?

I burn seasoned hardwoods and usually burn at temps. between 500* and 650* when things are hot. Of course things do cool down and I usually reload around 300*. I cut air back as much as possible which is usually 75% closed. If I try to go below that I end up with smoke out the stack.

I have liner swept 2x a season and there is usually powdery creosote that falls into the firebox that has to be cleaned out.

How much hotter do I have to take my insert to burn this stuff out so at sweeping time I don't have any? Or is it burning with air wide open for awhile. 8-/

 

[burntime]

I think they mean with the air control wide open to let the hot stuff up the chimney. Thats how I have always done it.

 

[jadm]

I think they mean with the air control wide open to let the hot stuff up the chimney. Thats how I have always done it.

Sorry, I need to ask a few more questions then. How long do you burn with your air wide open and how hot does your stove get during this process? How often do you sweep your chimney and how much creosote do you get?

 

[burntime]

I do this every morning for about 15 minutes or so and reload the stove keeping it open for another minute or two for the new stuff to catch and then damper down. I clean the chimney mid season and end to beginning and never have a problem. I just insulated my liner so it will probably be even less this year. If you think you smoldered the wood a little then do it a little longer. You will know if you are doing it right the first time you get on the roof to sweep the chimney.

 

[caber]

I let it burn until it just hits the overfire area on my stovetop thermometer. Then I cut it back.

 

[jadm]

I do this every morning for about 15 minutes or so and reload the stove keeping it open for another minute or two for the new stuff to catch and then damper down. I clean the chimney mid season and end to beginning and never have a problem. I just insulated my liner so it will probably be even less this year. If you think you smoldered the wood a little then do it a little longer. You will know if you are doing it right the first time you get on the roof to sweep the chimney.

How much creosote do you get?

How many pieces of wood do you have in the stove when you do this?

Thanks for the info.

 

[cgeiger]

Fwiw, I burned an old pre-epa VC Resolute Acclaim in my home 24x7 last season. I used well-seasoned to mostly well-seasoned wood the whole time and ran the stove at 450-600 degrees for most of the day. Imagine my stove temps as hills - as the fire died down the temps would drop off to the low 400's or upper 300's (center top) and we would throw on a couple of splits. At night we let it run down to embers and started fresh fires on the one or two remaining coals the following morning. Being that it was our first year burning and an old stove ($300 bucks delivered on Craigslist) I was a bit apprehensive about how dirty my chimney would be. I was obsessive about checking for smoke from the stack and rarely saw any past startup and the occasional piece of poorly seasoned wood.

As a further tidbit, I would get the fire crankin' (500-600) with the air wide open for a bit (old VC has a bypass damper system) and would watch as the creosote in the stove collar and flex pipe would start to glow and "burn" (kind of like watching a smoldering leaf well...smolder). It would work it's way on up the collar until I couldn't see it anymore and I would close the bypass damper back down again. I've heard some in other threads refer to this as "mini chimney fires" but that sounds a bit alarming to me What I saw was more of a slow, steady smolder - if I backed of the damper and opened back up real quick it would have gone out already.

Fast forward to last week when I had the sweep come and inspect my chimney. Most of what he removed from my chimney was a mix of creosote and birds nests (I had him install a top plate) from the smoke shelf as well as a cup (did I mention a cup) of creosote from the chimney. All told he took out a little over a gallon of crud from my chimney/fireplace and was extremely impressed with the performance we eeked out of our old stove. Burning seasoned wood is CRITICAL and burning hot is also critical (not to mention a good draft). I tried to always burn hot even if I had to burn smaller fires to keep from cooking us out of the room and I'm blessed with an incredible draft. Not sure if what I did was "right", but the results were pretty good. :D

 

[oconnor]

What is Hot to me?

Hot fire for me gives me 700-750 stovetop temp on my Jotul Kennebec insert - measuring surface temp next to the flue outlet.

Lots of flame, small kindling, lots of air - my goal is to heat my flue, so that the stove can then run well with the air turned down. Warm flue = good draft = good clean burn with dry wood.

 

[burntime]

I load the stove up and let er rip. I would guess I get about 2-3 cups of creosote when I sweep. Really, its good to be concerned but you setup is different then mine I am sure... Let experience be your guide and see what it looks like in a month, thats your best gauge.

 

[jadm]

Thanks for the tips and temps. and times listed here. I think I have a better idea of what to try and see what results.

 

[iceman]

Thanks for the tips and temps. and times listed here. I think I have a better idea of what to try and see what results.

when burning wood you are always gonna get something in the chimney
what you said in the beginning light grey powdery about 2-3 cups... is perfect so what ever you are doing keep doing it
when i reload i leave air open to get a good blazing fire then start closing the air in stages ... that blazin fire is heatin up the chimney
you are fine

 

[pen]

Hot is going to depend on the stove and thermometer placement. On my old fisher stove, if I were to leave the drafts wide open for 15 minutes (like some of you can on other stoves) this thing would go nuclear for stack temps.

Remember that if you are using a stove top thermometer it may not be gaining temperature as quickly as your stove / flue is. 1 problem is that the bimetalic strips in most thermometers act slowly and 2, the stove may not warm as quickly as the flue because of thicker metal, thermal mass of stove, and therefore at a steady cruise your stovetop thermometer can be a good judge of your burn, but on a quick start up where temps are changing rapidly I would be leary.

pen

 

[RedRanger]

Sorry Perplexed: but with all the high temps posted here, thought I had to chime in, because I really can`t see how anyone can come up with a magic temp.??

I burn wide-open on every re-load for approx 25-30 minutes and I only get 475 max. Usually my insert cruises at around 300-400 and it just churns out the heat. So much heat that I have to apply Noxema to my lower legs in the room with the insert because of the extreme heat..(no laughter allowed) :cheese: And now have the humidifier running down there.

There is no question that stove top temp is more than adequate, only clean the glass once a month, and zero,zilch, nadda in the way of creosote. Interesting question, when comparing the posts from the -- for eg. guys about running their summits up to 700-750 to get that desired heat. This insert doesn`t seem to need those kind of temps to produce more than enough heat.

Either that, or I have to invest in a second mag.therm to ensure accuracy?

Can also say that I shut the air control to less than 10% for overnite burn, and still clean glass and no creosote.

 

[brooktrout]

I let it burn until it just hits the overfire area on my stovetop thermometer. Then I cut it back.

I let it burn until it just hits the FAR end of the overfire area on my therm. :lol: No, really.....

 

[LLigetfa]

In the morning, I bring back the fire from a few coals with some smaller pieces that I cross pile to get lots or air. I do set the control wide open but the stove has a thermostatic air control so it will eventually choke it down after the heat soaks through all the metal but it does get a pretty good run on before that happens. I let it rip like that until it's burned down to coals and then stoke it up, turn down the coltrol, and head off to work.

 

[stockdoct]

I've heard, that to minimize creosote, you need to have a short, HOT fire once or twice a week. The suggestion was while a fire is going to open up your damper and put a wad of newspaper or cardboard box in the fire to get internal temperatures extremely high with immediate access to the chimney, for about a minute or two.

Sounds reasonable to me. Your thoughts?

 

[begreen]

Hot is more related to flue temps than stove top temps. Our first of the day fire typically sees 500-600 degree, probe flue temps. At that point the stove may still be warming up and be below 400 degrees on the stove top. This usually burning wide open or close to it for around 30 minutes. Or about what it takes to get a few medium splits burned to re-establish a good coal bed for daytime burning.

 

[jadm]

Thanks for all the input.

Glad to hear that others burn through several small splits when starting up. Thought I was doing something wrong - like somehow they shouldn't burn up so quickly....

Curious to try some of these ideas out and then see the results when chimney gets swept next month.

 

[chipsoflyin]

here's my routine, in the morning, shovel ash, rake remaining coal to the front, cross stack small splits in back and few pieces of kindling in front, open air all the way, let this load burn completely to coals, stack temps measured 18" up from collar usually get to 450 during this first burn, rake coal to front, load with splits to the top of the firebrick, open air all the way, when stack temps reach 500 start reducing air in stages, stack temps during the cruise range between 400-450 and the secondaries are lit. i have an older regency 1000s, this model has one secondary air manifold at the upper rear of the firebox.

 

[Backwoods Savage]

I do this every morning for about 15 minutes or so and reload the stove keeping it open for another minute or two for the new stuff to catch and then damper down. I clean the chimney mid season and end to beginning and never have a problem. I just insulated my liner so it will probably be even less this year. If you think you smoldered the wood a little then do it a little longer. You will know if you are doing it right the first time you get on the roof to sweep the chimney.

Whoa! Am I perhaps reading this wrong?

Perhaps you did not mean to word this as you did?! You are stating that you reload the stove and keep the draft open for a minute or so. That certainly is not long enough and if people read that it could cause a lot of problems for yourself and others.

 

[Danno77]

I keep reading people's claims of "i got X amount of creosote out when I swept" it's would be more meaningful to me if they included chimney dimensions/type. I mean are you running 30ft of 8" round insulated flex? 13 feet of a clay tile lined 12x12? I mean if you tell me that you got a cup, I might be impressed if you have a 25 foot chimney. If you have 8ft of chimney then I'm not as impressed. Alternatively if you get a full 5 gallon bucket full of creosote on a 35 foot clay tile lined chimney I wouldn't be AS worried as if you had a 15 foot 6" triple walled stainless chimney.

 

[cgeiger]

Danno77 - in reference to the dimensions of flue - mine is 13x13 with 6' of 6" flex from stove to first flue tile. The chimney is 23' tall and I had it swept after 1 full season plus 1 extra month of burning. Total creosote removed was a little more than gallon (not sure how much birdsnest was mixed in though). This was on a pre-epa stove. I expect my Oslo to perform way better once I'm finished with the install. Until then it's coooold in there.

 

[eernest4]

everybodies stove is different. Everybodies chimney is different. set up's vary greatly, as do the stoves.

Every fire , i start with 4 complete newspapers & then I run wide open until the magnetic thermo pins on the highest overfire temp and then I close the door & throttle down the primary air to 10 or 20 % open . I watch stack temp drop from 900* to 500* while stove top temp may come up to 250*-300*

I probably need to mention that my stove is 24 in x 24 in door (2ft x2ft) for 18 inches & then steps up to 2 ft x 3ft for the second 18 inches , being 3 ft deep over all and 2 ft steped to 3 ft high firebox. This is a huge steel monster front burner stove that I converted to secondary burn by changing the hot water pipes inside the stove to secondary burn tubes by drilling holes in them every inch. They leaked water into the firebox so they were useless for hot water but made killer secondary burn tubes.

Then I open the door & repeat, stack temp back up to 850 or 900 and close door & throttle down to 10 to 20% , while stove top temp may reach 400 or 450.

on the third repeat, of open door & stack temp to 800* (because by now , if I loaded a small wood load, I sometimes don't have enough wood left to get to 900* again) & close door & reset primary air to 10 -20& open & stove top will go to 500 or 550 deg & sometimes 650 deg

This depends on the wood that I am burning.
Usually only pallet wood will get me a stove top temp of 850 deg and it usually requires a fourth repeat of proceedure to get max stove top temp.

I have never seen my stove pipe glow or get red as someone described above but it does crackle , ting & ping and I usually see flames shooting up inside it through the crack of the joint
where two sections are fitted & screwed together.

These flames stop immediately as soon as I set the primary air to 20 %or less & stack temp immediately starts down for 500 deg or less.

After this fourth warm up , I sometimes get 800 deg stove top with 400 deg stack and other times I get 500 deg stove top with 250 deg stack.

These are my crusing temps , depending on wood load & type of wood and available draft that day. I am a free wood scrounger, so I usually burn a mixed load of hard & soft wood & pallet wood. maple,pine & pallet wood that is either pine or oak and maybe some pine lumber scraps.

Sometimes ,no two fires are alike.

unelse I burn just pallet wood,then all fires are closely similar.

I guess a lot depends on type and amount of wood & amount of draft that day.

anyway, I have 8 inch single black wall stove pipe in a 7 ft run through 2- 90 deg elbows to a 48 ft 12 x 12 tile chimney.

I have never had a chimney fire in the 4 years since I started burning & have yet to sweep the chimney. I took a good look down it (the chiminey) this summer & it seemed ok to me and it drafts so hard it sometimes keeps blowing the match out making it hard to light a fire.

This summer ,I will get a sweep and watch him hard, so that I can copy cat him ,next year.
Also, I will be highly interested to see what he has to say.

 

[begreen]

I do this every morning for about 15 minutes or so and reload the stove keeping it open for another minute or two for the new stuff to catch and then damper down. I clean the chimney mid season and end to beginning and never have a problem. I just insulated my liner so it will probably be even less this year. If you think you smoldered the wood a little then do it a little longer. You will know if you are doing it right the first time you get on the roof to sweep the chimney.

Whoa! Am I perhaps reading this wrong?

Perhaps you did not mean to word this as you did?! You are stating that you reload the stove and keep the draft open for a minute or so. That certainly is not long enough and if people read that it could cause a lot of problems for yourself and others.

It really depends. If I put a few dry softwood splits on a very hot coal bed, they will be fully aflame in a minute or two. And even if I damper all the way down, robust secondary combustion continues, sometimes for over an hour.

When you're trying to keep the stove top at greater than 500 degrees, this type of burning is not that untypical, especially in a big steel stove.