stinky jotul!

[vermont jotul user]

We have a Jotul 3, an older model with the catalytic converter. Directions state to get flue temp up to at least 600 degrees before engaging converter. We've used this stove successfully for two winters, usually running flue temp up to 800 degrees on the advice of our installer. So far this fall however, when running the flue temp this high the stove emits a horrible, almost burning rubber smell that permeates the house! The variables: Chimney (a selkirk metalbestos 6") has been rerouted slightly to accommodate a recent addition to the house. Two 30 degree angles were added. The outside height is slightly shorter than before, but well within the two feet higher than anything within ten feet rule. The other variable is that I cleaned the firebox thoroughly with my shopvac, actually dissassembling it (the firebox) to get into all the cracks and crevices. Yes, I did reassemble it properly! By the way, the chimney was just proffesionally cleaned.

Could a failed catalyst be my problem?

 

[begreen]

Can you locate the source of the odor? Is it the stove or the new pipe? My suspicion would be the new pipe, not the stove. Inspect the new pipe closely. Has it been painted? Is there any sort of caulking at the joints. What was used around the flue collar (area where the flue joins the stove)?

If it's not the pipe and definitely the stove, were any gaskets replaced?

 

[elkimmeg]

If you are suing a magnetic surface mount thermometer you are drastically over firing that stove. If an internal probe thermo things are ok


Here is what is happening the stove used to have the bottom seams plugged with ash now that it is removed the age of the stove your refractory joints may not be as good as you think
As mentioned the ash may have been plugging less than good joints. Now the joints are leaking and putting more air in that fire box. that smell is not usually a good sign usually telling you the stove is getting close to over firing. I also disagree with the 800 degrees. A cat will light off when the internal fire box reaches 500 to 600 degrees with the cat engaged you should not be seeing 800 degrees from your stack. If surface mount 300 would be more like it.

I do not agree with the advice you have received and think it is in error and believe you are over firing your stove

 

[jqgs214]

My bet the smell is coming from the new 30deg elbows that were installed.

 

[begreen]

Elk, the poster says - flue temps. Why assume the stove is getting out of control? The user doesn't indicate this is happening. Getting the stack up to 800 is not all that hard to do, but I agree that it is too high for normal stove top temps. 500-650 degree stove top temps on the F3 cat would be much more normal. 300 would be way too cool.

Vermont Jotul, how are you measuring the flue temps - with a surface mount thermometer on the flue or with a probe thermometer?

 

[webbie]

Keep in mind that any source of odors inside the stove would/should go up the chimney!

Did that stove have a top which just sat on, or is it bolted? You will want to check the seal of the top.

My first thought is that this smell will go away. It might be that you fired up the stove hotter than it has been (at certain points) and that paint, dust and other objects that might be on the pipe, stove - and especially below the stove (there is probably not a big bed of ash at the start of seasons)....so the bottom heat shields might have dust, etc. trapped int them.

That, plus any new internal piping, is my guess.

 

[vermont jotul user]

Using an internal probe thermometer approximately two feet up flue. Stove seems to be firing more quickly than before cleaning, there did seem to be cracks in one seam's sealant. There are two seams, one on each side of bottom. Does have the top that just sets on, but gasket looks good. Another clue, stove is "puffing" occasionally, sending smoke into the room from draft vent. Used to happen occasionally, but only in high wind conditions. The new parts of the chimney are in the attic, and smell is definately coming from stove or flue...

 

[webbie]

Personally, I would not monitor the stack temp (for operation) on this stove. I would monitor the top plate somewhere near the flue and look for 400-700, depending on weather and burn.

I think your problem will pass without too much action, so don't do anything drastic. Often customers would come in my store with problems and I would say it will pass - they would comment "but why didn't it happen before?", and I would pull out and dust off my favorite (and true) answer "there are no two days when the weather, wind, draft, wood and all other factors are exactly the same!". In your case, there was obviously a very good balance between the chimney and stove. My guess is that this has....however so slightly...changed. Not figure in the time of year, a hot fire, etc.

The puffing means that you are getting delayed ignition of wood gas. Lots of potential reasons for this, examples being that a stove has too much fuel in it and is turned down too far...the smoke builds up, and then hits some air (leak or otherwise) and some heat (maybe the cat), and it causes a min-explosions. We call this flashback or wood-gas explosion.

I would monitor it and see if it still occurs when stove is run relatively cooler than that.....a possible solution is a barometric damper on the internal stove pipe, which will server to balance the chimney and the stove.

 

[webbie]

To determine leakage through cracks, put a bright drop light into stove, turn lights off in room and look. You might have to put something over the glass door. Tiny cracks should not affect anything much. Larger cracks may let some excess air in. Hold a lighter up to these cracks when stove is running and see if they get pulled in.

If stove needs resealed, quick and dirty way is to clean and dampen seams from the inside, and then use your fingers and rutland black furnace cement - press into full length of seams.

 

[webbie]

A lot of posts, but keep in mind that the cat converter fires off at about 500 degrees, and is much more dependent on the temperature below it than what is 2 feet up the flue! So back to the idea of monitoring the stove. Basically, the cat should just work once the stove is all heated up. These tips are mostly for initial startup - i.e. you must have a decent bed of embers in the stove so the firebox area (and cat) are hot enough to work.

 

[begreen]

With more information from the poster I defer to Elk's suggestion of thoroughly checking the stove for leaks. Sounds like he was right on. The stove probably needs a simple rebuild or at least get those seams caulked before burning again. Do a light leak test and examine every seam carefully.

 

[vermont jotul user]

Well, so far, so good. I opened it up again and looked at the seams in the bottom--ALL of the sealant was compromised and flaked off when I started checking it. So I got a tube of stove cement for my caulk gun and resealed everything. No stench yet, no puffing, and it's not firing up so quickly now. I'm guessing it was excess draft from unsealed cracks in addition to parts of the stove getting hotter than previously due to the recent cleaning. Keep your fingers crossed for me!!

Now, next question, how often should I be cleaning my catalytic converter, and how can you tell if it's working properly?

 

[elkimmeg]

Glad I steered you in the right direction also glad you found the joints leaks. the cat how old is it? I usually clean it before the start of the season and at mid point. Misunderstood but if the get a bit clogged the next hot fire usually cleans them out To know if they are working s bring the fire up to a decent hot temp surface 550 engage the cat damper wait about 10 minutes has the smoke exiting the chimney decreased drastically Remember there is a bit of lagg time involved its not instant so look a couple of times every 10 minutes

BTW that's a nice looking stove

 

[North of 60]

This is kind of off topic but in the photo is that the actual home of the stove where it sits? Or was it pulled out to do your repair work?
Thats a wood floor isnt it? Curious.

 

[vermont jotul user]

Yeah, stove is not sitting where it is used. And by the way, I'm wondering why nobody thought to tell me the burning odor was because of the tape measure sitting on top! (check out the picture)

It looks to me that the smoke is not diminishing over time--is cleaning the catalyst usually enough?