F400 still wants to overfire at night

[rijim]

There are many pieces listed here that are correct so if you put it all together you can come up with a plan. It took me a full season to figure this puppy out. So work backwards, if you plan to hit the rack at 10pm and you know it take 6hrs to get down to a minimum set of coals, don't stuff the box when you get home at 6:00 at night or you will have too many coals left at 9:30 when you start to reload; half load will do it. If you reload on a full bed of very hot coals, when it takes off you have too much fuel off gassing and those wonderful secondaries will be raging. This stove likes the driest wood, moisture will cause you to give it more draft, the heat from a full bed of hot coals dries things out and off it goes with the extra air fueling the secondaries.
- So start with the driest wood possible.
- Don't fully load unless you have 6-6.5 hrs until next reload; only partial load if you don't have this time.
- Get wood fully engaged and charred before closing down damper (350-400 deg f stovetop).
- As outdoor air temp drops draft will increase so less air intake is required.
- A smoldering fire is inefficient and will creosote up your chimney so avoid it at all cost.
When very cold and I have my driest wood, 600 stove top is normal; throw an extra pot of water on and draw off more heat to create steam (970 BTUs). Keep a wad of aluminum foil near by; you can alway block the input if you start to climb past 700deg.
Good luck and let us know how you make out.

 

[Revturbo977]

Not long. It's not been very cold so we have let it burn out most nights. I've checked it a few times. Not really black, more brownish dust like coating on the chimney. It's not like the black on the glass in the morning .

Tonight was a better night . Raked the coals forward and opened the damper. Let the heat go down to about 350 and filled the box with 4 big splits and 1 small. Cracked the door and waited. Took a half hour to light the load. Once lit I started turning back the damper once it hit 400 . At 450 it was 1/2 open and 500 I had it down to 1/3. It then slowly rose to 600 with a good secondary burn. It's been sitting at 550-575 for about 20 minutes with the damper about 1/4 open. Letting her run.

 

[begreen]

Sounds good. You are starting to get the hang of it. It takes practice and working under different conditions with different wood. This is what makes an art out of burning well.

 

[Thislilfishy]

All good info. I've been fighting with my new stove as well. It loves to run up to about 725 and cruise there for an hour or so and then slowly back down. I tried everything, adjusted secondary intakes with magnets, installed damper on the flue. Different burn techniques, adding a wet split (30%) which did help a bit but not a lot. In the end what I found is that most of the wood I have is very small splits. On average about 3-4" at the thickest cross section, also my wood is very dry and 'aerated' by boring beetles of some sort. Then on a very cold night I loaded up the stove with very thick 6"+ splits...all from the same wood pile. Well...it was a completely different and fully controlled burn. Now when I have a load of the smaller splits I only load two rows instead of three, and when I have a load of the heavier splits I load it to the brim. So far I've only tapped 725 a couple times since learning this....both times with a fairly full load of the smaller splits on a bed of hot coals. I've never had an issue with the larger splits so far. I have a completely different stove btw, so your mileage may vary.

I bring the largest coals to the front and smooth out the remaining smaller coals to make a level bed for the wood to sit on.

Ian

 

[begreen]

Ian and Revturbo997 can you add your stove make/model to your signature line?

 

[Stretch]

Well, I got home late to a bed of coals, so I decided I'd treat the reload to a couple of north/south short
splits, and fill the stove with east/west splits on top of that. I raked the coals into the center of the grate
and proceeded like that at 10:52 PM. Ignition with the damper wide open at 10:55. Stove top at 200F; stack at
maybe 150F. 11:11PM the stack's at 320F, and the stove top is passing 500F - everything's fully involved.
By 11:17PM the damper is down to about 1/4 open, the stove top is around 650F, and the stack is running
about 310F. No visible emissions to speak of in the beam of my flashlight. Outside temp is 15F. ( I think I nailed
it this time! LOL! ) Off to bed.

Hope this helps, Turbo.

-Stretch

 

[Revturbo977]

Thought i had this figured out but no way After letting it go at around 600 and going to bed, my wife wakes me up saying the thing went past 650 so she closed the damper. Went to 750 and sat there. I don't get it. My wife said after I went to bed it dropped to about 550 and was running well, just before she let the dogs out she looked again and it was crankin again. As soon as the stove went past 650 she shut the damper. It took an hour for it to come back down below 650. I was happy to find a huge bed of coals waiting for me this morning so the restart was quick. Largest bed of coals after an over night burn so far. If my wife didn't check it last night the thing would have really taken off bad

 

[claydogg84]

When you say "shut the damper", are you talking about the air control, or do you actually have a pipe damper?

 

[Revturbo977]

Air control. I don't have one on the stove pipe

 

[claydogg84]

And I can't remember, have you verified these temperatures with a IR?

 

[claydogg84]

i don't let my Oslo get up to 600 unless I absolutely need more heat. Once it's going with the door open around 400, I'll close the door. 5 or so minutes later it will be around 450-500, at which point I will start knocking down the air. Some people can shut the air off completely, I can't without snuffing the fire out. I suggest you get the air completely off before going to bed, and starting the kick down process earlier than you were doing.

 

[Revturbo977]

Usually the air off will sniff the fire out at some point. It did after its little escapade last night . Left of closed and check it 2 hours later and the fire was still out.

 

[claydogg84]

Usually the air off will sniff the fire out at some point. It did after its little escapade last night . Left of closed and check it 2 hours later and the fire was still out.

Ok then I would suggest you start the air shut down process earlier than you have been. What temps have you been hitting before starting to kick it down? And have you verified the temps with a IR?

 

[Revturbo977]

What's an ir? I started turning it back at 400 last night. Hit 600 with it almost closed then crept down to 550. Sat at 550 for a half hour or so then took off

 

[firefighterjake]

What's an ir? I started turning it back at 400 last night. Hit 600 with it almost closed then crept down to 550. Sat at 550 for a half hour or so then took off

IR = Infrared Thermometer.

 

[claydogg84]

What's an ir? I started turning it back at 400 last night. Hit 600 with it almost closed then crept down to 550. Sat at 550 for a half hour or so then took off

Infrared thermometer.

http://www.amazon.com/gp/aw/d/B006V4WNYU/ref=mp_s_a_1_3?qid=1418122372&sr=8-3&pi=AC_SY200_QL40

You should be able to get one at your local hardware store, or Home Depot. Make sure you get one that reads past 800 degrees. Magnetic thermometers are notorious for being inaccurate. If in fact you are shutting down at 400, and it's still climbing that high, I would have to guess that maybe you are burning extremely dry, hard wood. Locust, hickory, oak, Osage? I can't get my Oslo to those temps unless I really try to do so.

 

[tarzan]

Ok, just a theory here so take it for what it's worth.

Your wet wood is now going to cause most of your problems. I'm thinking you are figuring out how to get the stove up and cruising but as the moisture is drawn out of the wood the variables change.

 

[Revturbo977]

My wood is far from dry. All mixed hardwoods all felled bucked and split in March

 

[claydogg84]

Ok, just a theory here so take it for what it's worth.

Your wet wood is now going to cause most of your problems. I'm thinking you are figuring out how to get the stove up and cruising but as the moisture is drawn out of the wood the variables change.

I gotta say if his wood was really wet I think he would struggle to get to these temps.

 

[claydogg84]

My wood is far from dry. All mixed hardwoods all felled bucked and split in March

So strange.. Wet wood in mine just smolders. What kind of wood?

 

[Revturbo977]

Mix of oak maple and cherry. Quite a bit of cherry.

I'm wondering when it was runnin nice at 550-600 then a half hour later take off was from the moisture burning off on the larger lower splits in the back of the stove , then started to release all gasses and burn like a mofo. Pretty sure it's a wood problem like Tarzan said

 

[claydogg84]

Where were the flames coming from? Once the secondaries are starting to die down, the wood itself starts to take over and burn.

 

[Revturbo977]

Last night was a secondary burn. Takes a long time to go back to burning the wood with a loaf that big if it's turned down

 

[claydogg84]

Last night was a secondary burn. Takes a long time to go back to burning the wood with a loaf that big if it's turned down

Should be about 1 1/2 - 2 hours of the secondaries.

 

[rideau]

Once your fire is established and you are t the air 1/4 open point, I would shut the air all the way, then just crack it open. You will probably revert to nice secondaries quite quickly. Watch for about three or four minutes. As long as you retain some flame and the coals stay red, I would leave the stove at this setting for the overnight.