Woodstove modification

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unit40

New Member
Hearth Supporter
Aug 17, 2007
83
Northern Massachusetts
I have been working on my Jotul 3CB install, and everything is going OK so far.

I chickened out on my original idea of venting through the rear knockout, because the top vent seems to work better. I took some advice and decided to delete the tee and barometric damper for now. Good thing a co-worker of mine is doing an install of his own and will buy my unused tee.

Last night I was able to remove the old thimble, which was really just black stovepipe, and install some nice stainless and got it all cemented in. I have all the pipe plumbed in loose for fit right now.

But I have a question about whether it is a good idea to modify the stove. I noticed that the primary air control slider, when closed down all of the way, is not really closed down all of the way. There is a stop, cast into the inner air deflector, that prevents the air control from shutting closed all of the way. I'm sure this is so that the stove will meet all EPA requirements and provide enough air for a clean burn. But I can't help wanting to pull out the air deflektor and grinding that stop off so I can turn the air down more if I want. Am I crazy?

Anybody consider doing this before? Should I just leave this thing alone and look forward to my first break-in fires? Why do I love to tinker with things so much?
 
Doing so will void your warranty.
 
i'd leave it alone. why chance caking up the chimney.
 
Learn to live with the stove a season first. If you are worried about strong draft, add a manual damper.

And be sure that you got the top back on correctly It must sit dead level on the gasket. Look at it from each side to be sure.
 
I would live with it for a season before making any modification. Aside from Wxman's point about voiding the warranty, which is a great one; a ton of engineering goes into those things to be sure they maximize heat output, efficiency and most importantly safety.

Don't get me wrong, I'm all about tinkering and improving also. I just like to be sure I know how something works and performs very well before I go messing with it.
 
I agree with your dislike of being "controlled" by the stove with the little stopper in there. Daytime running lights on my truck- disabled. Anyway, the better way to get around the stopper is by the installation of a butterfly damper which will allow you that control you desire without modifying the stove. If you want to cake your chimney with creosote than that's your choice.
 
OK OK,You guys are right. Thanks for talking some sense in me. Why fix it if it ain't broke, etc... I'll live with it and be joyously happy with my new unadulterated, highly engineered stove. I've been burning real clean with a couple of non-cats for the past 7 seasons, so why not just sit back and enjoy the fire!!!

Once i start attaching everything, I promise to check the top gasket. But I do question the stove adapter collar that came with the stove. On the underside of the top casting there are two removable stops that prevent the adapter from seating all of the way down to the "bead". When I removed them, the stovepipe adapter sat flush, and my stovepipe went in nice and clean. The install manual sais to install the adapter flush, but you cant with those stops in the way. Should I remove them, leave them in, the instuctions kind of contradict themselves, and I am feeling the strong urge to tinker with it again...
 
When my stove's air control is shut down it will burn well, but I don't generally feel like I want it lower.
 
Corie, I shouldn't do what? Start screwing with my new stove? I won't. I checked out some info today that stated that modifying a stove is illegal anyway. I guess I worry sometimes. When I first started burning, my wife tried to put too big of a log into this old Dutchwest stove we used to have. It immediately overfired, turned the pipe cherry red, the heat set off the smoke/heat alarm and the fire dept. came to the house. To make matters worse, she fired up a flare and stuck it in the stove thinking we had a chimney fire. The old Dutchwest Monster had to go. OK, I'll confess. I did it. So now I'm paranoid about having a fire in my house. I want a stove to be controllable and safe. I want my chimney to remain clean and safe too. I like my Jotuls and the Waterford because when you open the door....all is calm, they won't turn into a locomotive......
 
i imagine that the stop is there to disallow choking too far , im sure the engineers at jotul have the stop set at a "needed minimum" which should be low enough that it cannot run away , but will also not choke too far causing incomplete combustion and creosoted chimneys. cutting that away could be removing what is essentially a safety feature.
 
I'm worried about over firing and chimney fires too. I'm thinking about putting a damper on my outside air, so I can choke the stove off completely if I have to but leaving it open otherwise. I might even put a hole in the outside air ductwork just big enough to put a CO2 fire extinguisher tip in, if things get really bad.
 
Don't worry guys, the new wood stoves are very safe! They are tested VERY harshly and as long as you use proper burning techniques and clean your chimney, chimney fires and run away fires should be all but non-existent.
 
Maybe the most modern stoves are that way but my previous 90s model certified LOPI insert would gladly runaway with the draft slammed all the way shut. The EPA wouldn't allow that stove to be choked down either. Also don't forget that all it takes is a leaky gasket to make a stove go from "very safe" to runaway locomotive.

I think it would be a great idea to have a backupway to shut the air supply off to the stove in the case of a runaway or chimney fire. Not all Outside Air Kits provide a sealed path meaning that even if you plug the inlet, the stove could still find air from somewhere inside the home to feed the fire.
 
Highbeam,
You make an interesting point with that idea. an emergency shut-off for a woodstove. The EPA may test woodstoves the same way they test fuel MPG for cars. And you know what their record is for accuracy and results made during real world conditions/situations. Controlled laboratory conditions in many cases.
 
I'm no engineer, I'm no stove tech and I'm no genius on burning, but before I would take on modifying a stove for something better, I'd run it a while and learn what it could do. Every stove and burner maker had folk working to make a better stove. If you think you can out guess those folk, go for it. I would rather pick their brains for a better solution than think I can better them.
 
unit40 said:
Highbeam,
You make an interesting point with that idea. an emergency shut-off for a woodstove. The EPA may test woodstoves the same way they test fuel MPG for cars. And you know what their record is for accuracy and results made during real world conditions/situations. Controlled laboratory conditions in many cases.

There's no OAK option on the F3CB. Manual butterfly stack damper was all we ever needed to slow down a fire in the stove. Well, that and common sense. Try building a big fire out of full load of cedar or fatwood with a strong draft and you are in for a bit of excitement.
 
i've had my share of ah oh there that sound again. the advantage i have with this old stove of mine is i can see the air inlet on the back right next to the loading door. i run the old defiant and that guy likes to smoke. every once and a while it will be real cold and ya need to play catch up with the heat and ya get a good cranker going then you start hearing the crackling of the smoke pipe start and then it just keeps on getting worse. the advantage to my stove having the air inlet you can see is when that happens i stick a big glove type pot holder wedged between the back heat shield and the primary air inlet so no air gets in and in a matter of seconds everything is calmed down.

wouldn't be a bad idea to have the primary and secondary air inlet visable on all stoves just for that reason.
 
unit40 said:
OK OK,You guys are right. Thanks for talking some sense in me. Why fix it if it ain't broke, etc... I'll live with it and be joyously happy with my new unadulterated, highly engineered stove. I've been burning real clean with a couple of non-cats for the past 7 seasons, so why not just sit back and enjoy the fire!!!

Once i start attaching everything, I promise to check the top gasket. But I do question the stove adapter collar that came with the stove. On the underside of the top casting there are two removable stops that prevent the adapter from seating all of the way down to the "bead". When I removed them, the stovepipe adapter sat flush, and my stovepipe went in nice and clean. The install manual sais to install the adapter flush, but you cant with those stops in the way. Should I remove them, leave them in, the instuctions kind of contradict themselves, and I am feeling the strong urge to tinker with it again...

Not sure this has been addressed - I don't know the Jotul's but it would sound to me like if the stops are removable they possibly should come out if they are preventing a cast part of the stove from fitting properly - did they have something to do with securing the top plug if one was using the rear exit? Would they do anything to hold the adapter collar in? If you can figure out what they are for, that should tell you if they should come out or not. The other possibility would be to call your dealer or Jotul for advice.

OTOH, if what they are stopping is keeping the stove-pipe from going all the way to the bulge (leaving crimps showing) then they might be there to keep the pipe from protruding into the firebox, in which case you should trim the crimp end of the stove pipe until the bulge sits down on the adapter.

Hope this makes sense...

Gooserider
 
I removed the stops. Once I did, the stovepipe adapter fit snug. I checked my other identicle stove, and it doesn't have them, and the stovepipe adapter sits flush like this new one does with the stops removed. The stovepipe doesn't protrude into the firebox either once it is installed. I really can't figure why these stops are in there, but they're out now and everything looks correct both inside and outside the stove. And now the installation seems to comply with the manual's directions.
 
I don't know if the Jutols have a separate secondary air inlet or just 1 single primary air? But awhile back I remember a thread where someone built a slide to cut off the secondary air in his stove so he could bank the coals longer. If you have an exceptionally strong draft I don't see why it would be a bad thing to modify the air for more control except maybe warranty issues. Yes they have pipe dampers, but they can be a pain and just an extra control to mess with. First off tho I'd see how the stove performs this season then look into dampers or air control later.
 
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