Oak coals and temps - help!

[schmutzler03]

This is our second winter with the Buck 74. We have a basement rancher and use the stove to heat the downstairs finished portion and it sends just enough heat upstairs to keep the heat pump from turning on the auxiliary heat when the temps drop. We used a wide variety of seasoned wood last year, lots of softer species. This year we have primarily oak and maple and I'm seeing 3 issues:

1. I get the fire going and close the air vent once the stove front thermometer gets to 400. From there the burn goes well but now that I'm using mainly oak, it will usually get over 650 even with the air vent as low as I can set it. I know the magnetized thermometer is not on a part of the firebox that has direct contact with the flames, so once it gets to 650 I usually open the door to let some heat out. I am just wishing I could figure out how to keep that from happening. I guess less wood each load? Last year I'd load up the firebox pretty full each time, so I'm generally doing the same bc who wants to have to do it more often?? I don't think I can put a flue thermometer in with our insert set-up but am unsure. I'll send a pic of the collar/liner as can be seen through the 4" or so of clearance.

2. Also, the oak leaves lots of hot coals instead of burning to ash like everything else did last year. Last season we never emptied the firebox. Just tamped down the ash and the burns kept it reasonable. This week after burning 24/7 for 7 days I finally had to give in and scoop out coals because the box was halfway filled with ash/coal. I guess this seems like it's somewhat normal from everything I've read on here. I don't have a way right now to split the splits I buy from our local guy. I am having to assume they are as dry as the probe is indicating. They are not massive splits.

3. That leads me to my biggest perplexity - when should I reload? I usually reload when the thermometer indicates I'm getting close to 400, since anything after that says it's in the "creosote zone". I'm paranoid about the creosote building up . The chimney sweep commented this fall when we had the liner cleaned that we did well since there was little build up last year. I want to keep up that trend. But if I keep reloading at the 400 degree mark I end up accumulating the heaping stove full of coal chunks. Yesterday at 4:30pm I opened the air about 1/2 way and kept throwing on some bark, etc, for about 5 hours. It stayed in the "creosote zone" most of the time and really only made a small improvement in burning up the coals. Is it better to just bucket some of the coals every few days that to let the fire burn low like that every afternoon?

I'll include a few photos. First is the fire about an hour into the burn from an almost cold start. Second is about 4 hours after starting it, stove temp is about 450 and the third is just to show our set-up. Fourth pic is of our liner connection.

Thanks so much for your advice!

 

[MRD1985]

I reload at 200-250 when it’s very cold. 650 STT is not too hot. My regularly hits 700-725 when it’s cold with a full load of oak. I open the door on mine if I see 800 with a laser temp gun. Only use the magnetic stove top thermometer as a guide.

Open the air up fully to help burn down the coals once it gets near that stage. You can also try bark, and/or soft wood, like pine.

 

[gzecc]

Id guess your wood is not seasoned. Tell us how you measure the moisture content.

 

[schmutzler03]

Only use the magnetic stove top thermometer as a guide.

Here is the placement of our stt. I had figured since the outer metal isn't the firebox the stt would read lower than the actual firebox temp. Hence, opening the door when it got to 650.

 

[schmutzler03]

 

[schmutzler03]

Id guess your wood is not seasoned. Tell us how you measure the moisture content.

I read the moisture with a pin meter. Like I said I don't have a way at the moment to split it more and check the moisture further in. Our splits aren't super thick though so I hadn't been too worried about the reading being way off (12%)

 

[stoveliker]

Also, a cooling stove when it gets to the "creosote" zone at the end of a burn cycle is *not* creating creosote.
At the coaling stage this is not produced much.

You're fine letting it go longer. What you can do is put a small split of soft wood (pine?) on top and run it with wide open air.

 

[schmutzler03]

Also, a cooling stove when it gets to the "creosote" zone at the end of a burn cycle is *not* creating creosote.
At the coaling stage this is not produced much.

Obviously I don't know enough about creosote then - so is creosote just from what's happening at the beginning/mid burn? That makes me feel a lot better about just putting little stuff on the coals, though then it can be hard to keep the temps up to what we want.

 

[MRD1985]

Obviously I don't know enough about creosote then - so is creosote just from what's happening at the beginning/mid burn? That makes me feel a lot better about just putting little stuff on the coals, though then it can be hard to keep the temps up to what we want.

Try mixing species. Add some maple, ash, or cherry to the mix if possible.

top of the stove in the center is a preferable spot for the magnetic thermometer. I’d invest in a laser thermometer also.

 

[schmutzler03]

top of the stove in the center is a preferable spot for the magnetic thermometer. I’d invest in a laser thermometer also.

This is a fireplace insert that doesn't stick out from the brick enough to put the stt on. So if using a laser thermometer where/how would you recomend I measure for best accuracy?

Also, managed to hack into a piece of oak with a hatchet as that is the only tool I have on hand to cut wood and it didn't go above 15.2% in the piece I tried.

I will try mixing species. That sounds like it would make a lot of sense.

 

[MRD1985]

Mine is very close to yours as far as protrusion. On top in the center about 6” back from the lip is the hottest on my stove

 

[stoveliker]

Obviously I don't know enough about creosote then - so is creosote just from what's happening at the beginning/mid burn? That makes me feel a lot better about just putting little stuff on the coals, though then it can be hard to keep the temps up to what we want.

Creosote forms when water (and wood alcohol etc) condenses on the walls of the flue and then captures smoke particles.

So you need water, low enough temps and smoke.
Most of that is present when one chokes the fire too much, and especially in the first stages of the burn.

Water will always be produced during a burn but it's much less at the end, and generally the exhaust is also cleaner (less smoke) in the coaling stages. (Little blue flames are the cleanest ones.)

I do get enough heat out if I add a 2" thick split on a "dike" of coals located where my air hits it. If course it means "reloading " after a short while.
At least I get more heat out then just trying to burn the coals down on their own.

 

[schmutzler03]

Mine is very close to yours as far as protrusion. On top in the center about 6” back from the lip is the hottest on my stove

Yeah, mine is only a 3.5" protrusion from the surround panels

 

[schmutzler03]

I do get enough heat out if I add a 2" thick split on a "dike" of coals located where my air hits it. If course it means "reloading " after a short while.
At least I get more heat out then just trying to burn the coals down on their own.

Thanks for giving me a better understanding of what causes the creosote.
I have been trying to rake the coals into a heap in the center right in front of where the Buck air inlet is without blocking it. I will experiment with the 2" splits as I've got many of those around. I"ve also noticed this year that the bottom of the glass isn't really dark, but isn't as clean as last year too. Just slightly hazy. Kind of expected even more to find the oak was too wet when I noticed that, but doesn't seem to be the cause. IDK.

 

[all night moe]

I have been trying to rake the coals into a heap in the center right in front of where the Buck air inlet is without blocking it.

I'm using a wood furnace and currently burning down the coals before the next load. Air intake is in the door itself and washes across the whole bottom. I rake my coals forwards and then level them out. They provide more surface area for the air to "wash" them. I usually let them go on their own with another raking about 20-30 mins in. If I'm in a hurry to burn them down, bark or a small softwood split helps. So does what I call splitter slag. The bits and chips from splitting wood.

 

[xman23]

Run the stove to keep the house at the temp you want it. That will change a little or a lot based on outside temps. If you need heat and the hot bed of coals is not enough, Load a split or two on top of the hot bed. Just avoid a smoldering fire.

 

[schmutzler03]

Looking at the liner type we have in my first post (there is insulation a few more inches above the area I could photograph) can you use a probe type flue thermometer or should I just get a laser temp gun as mentioned?

 

[stoveliker]

I think it's possible.

 

[kborndale]

I read the moisture with a pin meter. Like I said I don't have a way at the moment to split it more and check the moisture further in. Our splits aren't super thick though so I hadn't been too worried about the reading being way off (12%)

If your not resplitting the wood you are not getting an accurate reading of the outside of your wood is reading 12% then the inside of your wood is over 20%. Unfortunately buying wood that is ready to burn is rarely possible even though every dealer says their wood is "seasoned". You need to get at least a year ahead on your wood.

 

[schmutzler03]

If your not resplitting the wood you are not getting an accurate reading of the outside of your wood is reading 12% then the inside of your wood is over 20%. Unfortunately buying wood that is ready to burn is rarely possible even though every dealer says their wood is "seasoned". You need to get at least a year ahead on your wood.

Next week when I get my chainsaw blade back I'll try cutting a few splits in half and checking the internal moisture. Earlier I stated I managed to hack into a piece of oak with a hatchet (as that is the only tool I have on hand to cut wood) and it didn't go above 15.2% in the piece I tried. I only got about 2" into a 6" split though.

So when buying wood from a dealer you recommend buying it a year ahead it sounds like? Have no truck or other way to haul wood myself so I'm stuck with buying from others.

 

[Eman85]

When buying wood I'd want to buy a few years ahead, not 1 year. I think for a moisture meter to read you have to have the pins in lengthwise grain of the wood, not a cross cut. I don't understand your original problem. I wake to a well burned load of coals every morning and I open the air wide open and enjoy the heat, I'll let the coals burn like that until they are a low layer of orange glowing mass and I reload over the top of them. I never scoop out coals, just let them burn. The temps will drop when the coals burn down but coals aren't creosote creators. My coals have been burning down for 3 hours now and I'm going to hot reload over them.

 

[schmutzler03]

I think for a moisture meter to read you have to have the pins in lengthwise grain of the wood, not a cross cut. I don't understand your original problem.

That's how I use the meter. Took a whole section out of the split wide enough for the pins to fit in there lengthwise.

The overnight burn is fine. It's usually down to about 200 stove front temp after 8 hrs and very small coals. I was just trying to figure out how to keep the heat up during the day. That's when I have to keep reloading over big coal chunks. Those build up quickly even just throwing in one or two splits every 4 hrs. I believe the suggestion of mixing in softer woods will help this.
Seems another major factor is the stove is in the finished half of the basement - on the gable end of a ranch. The only way for warm air to get up to the main floor and cold air to get down is through the stairwell in the center of the finished space, about 20 feet from the stove. So we usually have to keep the basement in the high 70s-80 for enough heat to help the upstairs hvac not run a ton. Haven't convinced my husband to let us install another small stove just for the upstairs yet, but the cat and I are working on it.

Since this is only my second burning season with the stove I've been trying to tease out what I need to correct, what's normal and what is just the limits of the Buck 74 in our basement rancher. I've read endless threads on here over the past year and gained so much information (that is sometimes conflicting, but hey, oh well!) from the replies. I've experimented a bunch with fans and air movement and really appreciate everyone who has chimed in.

 

[all night moe]

Took a whole section out of the split wide enough for the pins to fit in there lengthwise

The pins need to be pressed into the wood. Buried as far as possible, Not stuck into a void.

 

[stoveliker]

Mixing in soft woods in the main loads just scales the coals to the hard(er) wood fraction. I.e. half pine half oak gives you half the coals.

At the end of a burn raking them to there where the air hits it, putting a small soft wood split on top (one that takes off quick and burns fast and hot), running it with the air open, helps burning down the coals and (in my case) provides sufficient heat to either stop or decrease the cooling of the home to an acceptable level for an hour or two. Moreover, having (me too) a basement stove, the heat in the basement acts like a reservoir that decreases the immediate influence of that lower output.

Finally, I move heat from the basement through the stairs just like you. I do it like this.

Post in thread 'Moving heat from basement'

May 1, 2023

I heat from the basement, and if I include my basement squre footage, I have 2500 sqft.
825 in the basement and 1700 above that. Late 70s. Brand new triple pane windows, fantastic sealing and insulation (R57) in the attic. Mediocre wall insulation.

My basement walls are insulated, but the floor is unfortunately not.

Heating my home above the basement is easy. Only when it gets to be 5 F do I have to push the stove (as in 8 hr reloads), still keeping my main floor around 70 F.

However, I second the comment above that heating from a basement benefits from consistency, i.e. you heat...

• stoveliker

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[schmutzler03]

The pins need to be pressed into the wood. Buried as far as possible, Not stuck into a void.

Sorry to not explain enough . I pressed the pins well into the newly exposed wood, along the direction of the grain. I think I did it right. I owned this meter for home remodeling projects before I owned the stove.