I am new to wood burning and I have a Jotul f500 that was professionally installed. I often have a lot of odor when the fire has mostly burnt down. It bothers my nose and eyes a bit. When the fire is burning strong it is generally not an issue. The stove is setup rear exit through 18" of double wall pipe that goes into my garage and up 15', about 10' of the pipe is inside my garage which never really drops below 50. Any suggestions?
Smell as fire burns down
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Hard to say without seeing the set-up. Do you think the odor becomes an issue even when the door is closed or is it possibly due to smoke spillage when the door is open. Spillage when the door is open can be a sign of inadequate draft. Sometimes it helps to open the door slowly to let the air currents in the firebox get adjusted to the new configuration.
If you smell smoke when the stove is burning normally with the door closed, that is a big red flag something is wrong. It would probably be best to get knowledgeable eyes on site to check it out.
One other question - are there any additional unused flues in the set-up? Sometimes a stove can pull odor back through an unused fireplace, etc. But if you have a single flue, that should rule this scenario out.
If you smell smoke when the stove is burning normally with the door closed, that is a big red flag something is wrong. It would probably be best to get knowledgeable eyes on site to check it out.
One other question - are there any additional unused flues in the set-up? Sometimes a stove can pull odor back through an unused fireplace, etc. But if you have a single flue, that should rule this scenario out.
Have you checked any loose joints in the pipe from the stove to the double wall? Perhaps when the temperature drops, the low draft allows some odor to escape out somewhere. When your draft is strong, it is pulling in room air through these areas and there is no smell.
LLigetfa
Minister of Fire
It sounds like poor draft combined with a pressure deficit resulting in products of combustion leaking back into the home. If you crack open a window near the stove, is there an inrush of air? The pressure deficit may be from stack effect and insufficient makeup air supply to the home. Seal up where airr is leaking out and let more air in. An OAK should help.
cozy heat said:
There is no odor while the fire is burning strong with the doors closed. If I load the stove and close the doors I am odor free for a good 3 hours. As the fire burns down to just near coals I begin to smell it.
cozy heat said:
No other fireplaces, only a gas stove in the basement. Chimneys are about 35' apart and I do not smell smoke in the basement.
Nic36 said:
This is what I suspect is happening. I have a Selkirk Ultra-temp chimney. The double wall goes right to the stove with the single wall adapter being pushed right into the back of the stove. Should the joints between the sections sealed with anything?
LLigetfa
Minister of Fire
A flue relies on heat to create draft. The more the heat, the more the draft. When the fire burns down to coals it no longer provides as much heat to service the draft. That combined with a negative pressure situation can result in what you describe.
LLigetfa said:
I haven't tried an open window when near the end of the burn. I will do so today and report back. Assuming that works, is the OAK the answer?
LLigetfa
Minister of Fire
I don't think just one fix is called for. An OAK should help but there are other factors. Adding more height to the chimney will also help. Balancing the air in the home is also important.
cycloxer
Minister of Fire
For sure you have a draft problem. My brand new Jotul F 400 Castine has exactly zero smoke at any point of the burn even if I am at full close on the air and am burning not so dry wood.
You can seal all of your pipe joints with furnace cement, but that is a band-aid solution and not a fix. I would still inspect every pipe joint and make sure you have no gaps or leaks. If you see any, bust out the furnace cement, it's $5 and you can do this yourself.
Can you insulate your chimney pipe? It may be cooling down too quick in the garage. You want to keep your chimney pipe warm so that you maintain a good draft. Can you run a top exit instead of a rear exit? Rear exits on Jotuls draft worse.
Finally, does your furnace have a make-up air blower? Are there any other blowers or fans in the house that could be causing a negative internal pressure?
EDIT: replaced stove pipe w/ chimney pipe
You can seal all of your pipe joints with furnace cement, but that is a band-aid solution and not a fix. I would still inspect every pipe joint and make sure you have no gaps or leaks. If you see any, bust out the furnace cement, it's $5 and you can do this yourself.
Can you insulate your chimney pipe? It may be cooling down too quick in the garage. You want to keep your chimney pipe warm so that you maintain a good draft. Can you run a top exit instead of a rear exit? Rear exits on Jotuls draft worse.
Finally, does your furnace have a make-up air blower? Are there any other blowers or fans in the house that could be causing a negative internal pressure?
EDIT: replaced stove pipe w/ chimney pipe
LLigetfa
Minister of Fire
Stove pipe or chimney? Insulation is not to touch the stove pipe or chimney. Double wall stove pipe will retain a bit more heat to service the chimney. Chasing in the chimney with proper clearance will keep it warmer but I suspect you want the heat from it.cycloxer said:
cycloxer
Minister of Fire
Right. You know what I mean. He has to figure out how to keep the chimney pipe warmer to maintain the draft as the stove burns down.
LLigetfa
Minister of Fire
Yes, I understood what you meant. The point was to add clarity for others.cycloxer said:
It all boils down to a balance. There are forces both inside and outside and the inside forces need to balanced with the outside forces. Creating more draft to overcome other forces is just one end of the balance. Adding more flue is usually better than sending more heat up too short of a flue, but the pressure in the room still needs to be addressed.
cycloxer
Minister of Fire
Yup, fully agree - if the chimney is a lot shorter than 15', adding some height could do the trick.
Thank you for all of the comments and suggestions.
I tried a few things and made one other observation:
1) sealed where the adapter goes into the stove. This seemed to help a bit but did not solve all of the problem.
2) it is hard to tell if opening a window is helping in any way. I do know it is not eliminating the issue but I will continue to burn like this to form more of an opinion.
I notice if I open the front door after the fire has burned down (but still have red coals) I get rollout. I tired opening a window near the stove then opening the door and I still get rollout. The stove top is 250f at this point and the chimney in the garage feels hot. You can put your hand on it, but only keep it there for 3-5seconds. I am guessing it is 110-130f.
All of my piping is 6" Selkirk double wall pipe. It has an 18" horizontal section then 15' vertical. It clears the top of my house by 24". Is adding another 3' section the next logical move?
I tried a few things and made one other observation:
1) sealed where the adapter goes into the stove. This seemed to help a bit but did not solve all of the problem.
2) it is hard to tell if opening a window is helping in any way. I do know it is not eliminating the issue but I will continue to burn like this to form more of an opinion.
I notice if I open the front door after the fire has burned down (but still have red coals) I get rollout. I tired opening a window near the stove then opening the door and I still get rollout. The stove top is 250f at this point and the chimney in the garage feels hot. You can put your hand on it, but only keep it there for 3-5seconds. I am guessing it is 110-130f.
All of my piping is 6" Selkirk double wall pipe. It has an 18" horizontal section then 15' vertical. It clears the top of my house by 24". Is adding another 3' section the next logical move?
cycloxer
Minister of Fire
How much rollout are we talking about here? Do you crack the door open, pause for a few seconds, and then open it fully? That's the correct way to open a stove door. It sounds like you have a weak draft if you get a lot of rollout. Is the 18" horizontal section pitched up properly away from the stove? I think it is supposed to be 1" for every foot or so.
I would say a little rollout. I do crack the door then open slowly. The 18" section has very little pitch on it. I would say an 1/8". Adding another 1" is going to be a pia, but it is something I should be able to get the installer to do. I had called them this morning to discuss the issue and I am waiting for a call back.
Assuming I do have a draft problem what is the best way to fix it?
Assuming I do have a draft problem what is the best way to fix it?
cycloxer
Minister of Fire
You need at least some rise on the horizontal run. The more the better. What kind of stove do you have? My Jotul calls for 1/4" rise per foot.
It is a Jotul Oslo. It is all done with Selkirk Ultratemp piping. I am not sure how much flex the joints will have. Still waiting to hear back from the installer. If it is a 1/4" per foot it sounds like I only need 3/8" of an inch and I already have an 1/8". I think this is do able without any major changes.
cycloxer
Minister of Fire
Ah, I just now noticed you have the 18" vertical pipe coming out the back of the stove. I sorta missed that earlier. I have a total of 10 feet of double wall class A chimney and about 5 feet of single wall pipe inside. So, about the amount same length as you. My chimney doesn't even extend above the roof line and my draft is fine with no smoke rolling out when I open the door. Oh yeah, my chimney is all vertical.
So, from what others said, it sounds like that vertical 18" section with the rear outlet is killing your draft.
It doesn't help your situation, but I have to ask, why didn't the installers just go straight up? Was there an issue preventing that?
I don't guess it would hurt to add some more chimney up top, but I know that's extra money, and no definite guarantee that it will fix the problem. Plus, if you go over five feet of chimney outside, you need to brace it. But, if the installers are willing to try it with a section of their pipe, it would be worth it.
So, from what others said, it sounds like that vertical 18" section with the rear outlet is killing your draft.
It doesn't help your situation, but I have to ask, why didn't the installers just go straight up? Was there an issue preventing that?
I don't guess it would hurt to add some more chimney up top, but I know that's extra money, and no definite guarantee that it will fix the problem. Plus, if you go over five feet of chimney outside, you need to brace it. But, if the installers are willing to try it with a section of their pipe, it would be worth it.
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