How do you suppose to control an EPA stove?

[n6crv]

Hello, I did a search and could not find an answer so hope this has not be asked. My old stove you just loaded it up and if it started getting to hot close the air. My new stove a 13NCP has been a great stove for putting out heat but a pain to control. I have had trouble with getting it really going during start up but think I got that under control. Last night after it had been running all day I was ready to call it a night. I had a good 3" bed of coals so added 3 good size splits to the fire one I would even call large. The air control was pulled about the normal for me 1/4 to 3/8" to get the logs going. As soon as they were flaming good and started to get charred and secondary burn going, I closed the air to just about off. Started turning lights ect. off and noticed the fire seemed to really be taking off. I closed the air off and that "did nothing" it just kept getting hotter. The secondary tubes had a nice glow and feeding the fire. Well the stove top temp was going up the flue temp was going up. I turned the blower on high and that did very little. How in the world do you shut one on these new stove down? I'm using a OAK tube going from the stove to a window. It was icy and windy last night so that might of added to the trouble. Do you think it would help to put a damper in the flue pipe? I don't think I could have a over draft problem as there is only 17' of chimney/flue above the stove. Did not have this trouble till it started getting colder out. Also if the stove gets all of it's air from the OAK can I add a damper in line with it. I really need to use the OAK as I use oxygen so that has been great getting the air from outside. At this time I don't really trust it burning at night if it is going to take off again like it did. THANKS for your help.

PS: I know that I can be a pain with all my questions, but y'all have been great.
Don

 

[webbie]

Don, you are somewhat correct in the dual nature (dichotomy) of newer stoves. When you think about a fairly large wood fire at "critical mass" with the air inlet shut, you understand that it MUST be putting off a lot of smoke! But a newer and properly operated cat or non-cat is BURNING that smoke, thereby creating heat! So it is quite common...we hear it in the forums a lot lately.....for folks to wonder why the stove gets hotter when the air is turned DOWN. But it makes sense when you think about it. In fact, anyone who operated an older stove with a turn damper can tell you the same thing. You could feel the additional heat come out of the stove when you turned that damper down (at the coal stage!).

My guess at the solutions have mostly to do with getting to know your stove. You might find tat you can rake the embers and favor one side (end) or the other of the stove, and thereby have less wood burning at once....as long as you keep the secondary burn you will be OK.

Then there is the obvious, using less wood on a load and bigger splits, etc.

So in some ways, the answer is that once you start that thermonuclear reaction with a full load of good wood and great embers....it is tough to turn it down!

 

[BrotherBart]

Yep been there. It gets exciting. The best way to do it as far as I have found is to have the stove cool enough at loading time to handle the blast of gases that come out when that fresh wood gets to around 225 degrees and goes into gasification stage. This give the stove body some wiggle room to absorb some extra heat as the gases burn and you a little working room to control the progression of the burn.

Had an interesting burn situation myself last night. Stove loaded with a large log across the back and two big splits in front of it. Burn gets established and runs at a stove top temp of 550 or so for two hours. At the two hour mark that back log finally got enough heat to gasify and the temp went up to 650 with the full light show just like a stove at start up. Sleepy as I was I decided it was time to roast on the couch until I saw how that played out.

 

[chad3]

BB,
Had the same thing happen last night. Was about to go to bed, but a great mix of Maple, Ash, and Oak in the fire caused the temps to go up to around 550-600 temp at back corner of stove. Seemed to level off there and stayed for about 1/2 hour, called it good no more increases went to bed. Is there another increase that I don't tend to see? I usually notice after the first real increase my Oslo seems to taper off and maintain not going higher, settling in and then slowly declining. Just curious.
Chad

 

[BrotherBart]

This was the first I have seen. I have been burning it side to side instead of front to back for a few days to see how it burns and this was the first second spike have seen. It was definitely caused by the late gasification of the big log in the back. Had it been a split I think it would have gasified at the same time the others did. And given the temp when they did that could have been a whole 'nother interesting situation.

 

[begreen]

Have seen this on my Jotul as well, though not too frequently. It happened with a fresh load of dry fir on a big bed of hot coals. The other time was as I was learning about the wallop of too many of the Homefire Prest-Logs.

When the stove did peg the needle at 750 with the Prest-Logs, I cut off most of the outside air temporarily to slow it down. That was pretty effective. I resumed burning at about 650 and it was well behaved again. So I wouldn't use an OAK damper as a day to day regulator, but it may be an appropriate emergency brake for these occasions.

Now I have learned to burn the coal bed down quite a bit first, about 11 pm, then put down a couple small sticks and then my night wood on top of that. I have big thick soft maple splits that burn slowly and work well as night logs. I haven't had a runaway yet this year. (knock on a log)

 

[rad3110]

Striker C160 insert 6 inch offset adapter 20 ft 6 inch liner. Im getting a bit jeleous hearing about these high stove temps. I was able to ping off 500 degree's once but average between 350 and 400 degrees. I guess thats as good as the little stikers going to get. Ive tried several types of woods. Oak so far the most abundant and best burner. Long Island NY

 

[BrotherBart]

Striker C160 insert 6 inch offset adapter 20 ft 6 inch liner. Im getting a bit jeleous hearing about these high stove temps. I was able to ping off 500 degree's once but average between 350 and 400 degrees. I guess thats as good as the little stikers going to get. Ive tried several types of woods. Oak so far the most abundant and best burner. Long Island NY

Same with the little Jotul F100 in my office. Just load and let'er rip and it hangs out around five hundred. Small firebox doesn't hold enough wood to get into serious gasification lift-off trouble.

 

[astrodon]

FWIW, On my NC30, the primary burn on the bottom pretty much dies completely when I close off the air. The coals quickly go from white hot to fairly dark with little glow. Once this happens, my secondary starts deteriorating and flue temps slowly go down. On the one overfire scare I had, the stove top was at 825 degrees Rutland and rising. Just nudging the air barely open caused the fire to liven right up, so I closed it up, put a fan gong across the stove top to capture some of the excess heat, and waited until the temp hit about 600 with the fan off. It took a good fifteen to twenty minutes for this to happen though

This was the first I have seen. I have been burning it side to side instead of front to back for a few days to see how it burns .....

I've seen this mentioned before.. How do you burn either side to side, front to back, or back to front? Are there advantages to each when it comes to burn times and or temps?

 

[Jimbob]

Raking all the hot coals to one side of the stove, then reloading will give you a side to side burn.
Raking the embers to the front before reloading will give you the front to back burn.
Pushing the embers to the back of the stove would in theory give you a back to front burn, but this usually doesn't work, because the air inlets on most stoves are towards the front of the firebox.

 

[BrotherBart]

I've seen this mentioned before.. How do you burn either side to side, front to back, or back to front? Are there advantages to each when it comes to burn times and or temps?

I burn it both ways according to the mood I am in. Front to back is much faster startup. Side to side gives more consistent secondary burn and a little longer overall burn. The way the primary and secondary air inlets are set up it is built for side to side. I just hate going through the drill of getting a side to side burn started up.

Want a real blast-off? Load the bottom row of split front to back and the top row side to side with an inch of airspace between them.

Then duck.

On your point about primary and secondary. The stove increases secondary air as the primary is decreased. The air control affects both. I get the best burn with the stove at 500 - 550 with the air control about ten percent open. It lets the primary air blow the gasses from the front of the stove back into the secondary burn where they get consumed.

Also I don't do the balls to the wall startup looking for the light show. That just consumes the gases from the gasification stage too fast with too little heat output. I start backing down the air control when the stove reaches 400 and ease it down to ten percent or so as the top approaches five hundred.

Finally, if your stove is free standing and not confined in a fireplace, if it starts to run away on you there is hope. The secondary enters the stove through a fixed square hole in the bottom of the back of the stove behind the primary air inlet. If the stove takes off on you slap a heavy piece of tin foil over the hole to choke off secondary air. It won't kill all of it but the stove will start coming back down pretty much immediately. You can't completely cut off primary because there are intentional spaces around the box where the primary comes in that are not welded. On purpose to meet EPA requirements.

 

[QuailRunner]

Finally, if your stove is free standing and not confined in a fireplace, if it starts to run away on you there is hope. The secondary enters the stove through a fixed square hole in the bottom of the back of the stove behind the primary air inlet. If the stove takes off on you slap a heavy piece of tin foil over the hole to choke off secondary air. It won't kill all of it but the stove will start coming back down pretty much immediately. You can't completely cut off primary because there are intentional spaces around the box where the primary comes in that are not welded. On purpose to meet EPA requirements.

Any info on where to put a piece of foil on a Vermont Castings Encore NC to close the secondary draft port? I'd like to have this info as a last resort; I've had a few high-temp experiences in the two years that I've owned this stove. BTW, I recently replaced the gasket around the ash door and the main doors, following the advice of my dealer. This (with some latch adjustment) has made a large difference in the control that I have over the stove. I've also installed a manual damper in the pipe (I know that the stove isn't supposed to have one), but have not needed to use it yet (its only down to 20 F outside; when the temp drops below zero the draft in my 20+" lined chimney really gets going). My stovetop temp runs about 600-650 afater reloading; this heats the house up a lot. The documentation on the stove indicated that it (1900) was for a house a bit bigger than mine (1400); I'll take that as gospel truth next time, but I'm happy enough with the stove as it is.

 

[QuailRunner]

BTW; my stove is burning at high operating temp right now, and I decided to try a tip that (I think) I read on one of the threads here; open the baffle. I did this for about 15 minutes, and the stovetop temp dropped right off from 675 F to under 600 F. Clearly, the postings indicating that the afterburn system creates a lot of heat are correct.

 

[Gunner]

N6,
Like BB said, the answer is to let the stove cool off abit before reloading. If your at 400deg with a big coal bed and load it up for an overnight burn, it is going to RAGE...the stove is just doing it's job.

Knowing how much wood to load in the afternoon to keep you warm and have enough coals for a relight, but be cooled down enough in time for your overnight burn is the ART part of woodburning.

 

[n6crv]

Thanks for all the help. I will try not to feed it as often. Really like the stove and the way the chimney has been staying clean. Guess alot of the trouble is just getting used to a new stove. Have a good one and stay warm.
Don