Draft problems?

[wetwood4life]

Going into our 3rd year burning... new stove, new through-wall chimney, new operator. I think we have poor draft, but don't know how to troubleshoot anymore or fix it.

1. If the stove door is open, we'll get continuous smoke into the room
   1. Doesn't matter when in the burn cycle
   2. Doesn't matter if the front exterior door (same room) is wide open
   3. Doesn't matter if I leave the stove door cracked for a few minutes beforehand
2. We commonly have a strong cold downdraft
   1. Downdrafts are stubborn - even lighting newspaper in the flue will still push smoke into the room
   2. Slightly worse with the bathroom fan or boiler running, but it's a problem even when they're not running
3. Recently I noticed the smoke usually lingers in a ball around the chimney cap and tends to drift down.

Our stove calls for 10-30 feet from the floor to the chimney cap. We have a "through-wall install" (random pic from the internet below) with about 16ft outside and 5ft from the floor inside.

I've burned ~1 cd each of the past 2 winters. Two chimney sweeps have confirmed no excessive creosote. They both said the install looks fine, but if we have draft problems they would install one of those spiral wind caps to prevent down drafts. I don't think that's it because this is always a problem, and no worse on windy days.

Last year someone here suggested stack effect, and our leaky attic "fighting" the chimney. We got the attic air-sealed and insulated over the summer. It makes a big difference in keeping the house warm, but the stove still streams smoke into the room.

We have zero confidence in the original installer since they shoddily slapped everything together without doing any site or room planning, so it feels like I need to figure it out myself unfortunately.

Any advice?

Thanks,
Dan


photo credit: https://www.northlineexpress.com/help-pipe-install-planning.html

 

[NickW]

Is this only on cold starts or on reloads also? I assume it's worst on cold starts... Try a hair dryer, candle or torch to pre-heat the flue and establish a little draft then build a small hot fire that'll take off quick and heat it some more. If reloads are also an issue do a small hot fire to re-establish draft.

Some setups are prone to draft issues due to configuration. Find what works best for you. Our NC30 at home with a horizontal run drafts well in our '78 construction house. The Stratford II ZC up north that goes straight up takes a little work in new construction even with the outside air intake.

 

[begreen]

Going into our 3rd year burning... new stove, new through-wall chimney, new operator. I think we have poor draft, but don't know how to troubleshoot anymore or fix it.

1. If the stove door is open, we'll get continuous smoke into the room
   1. Doesn't matter when in the burn cycle
   2. Doesn't matter if the front exterior door (same room) is wide open
   3. Doesn't matter if I leave the stove door cracked for a few minutes beforehand
2. We commonly have a strong cold downdraft
   1. Downdrafts are stubborn - even lighting newspaper in the flue will still push smoke into the room
   2. Slightly worse with the bathroom fan or boiler running, but it's a problem even when they're not running
3. Recently I noticed the smoke usually lingers in a ball around the chimney cap and tends to drift down.

Our stove calls for 10-30 feet from the floor to the chimney cap. We have a "through-wall install" (random pic from the internet below) with about 16ft outside and 5ft from the floor inside.

I've burned ~1 cd each of the past 2 winters. Two chimney sweeps have confirmed no excessive creosote. They both said the install looks fine, but if we have draft problems they would install one of those spiral wind caps to prevent down drafts. I don't think that's it because this is always a problem, and no worse on windy days.

Last year someone here suggested stack effect, and our leaky attic "fighting" the chimney. We got the attic air-sealed and insulated over the summer. It makes a big difference in keeping the house warm, but the stove still streams smoke into the room.

We have zero confidence in the original installer since they shoddily slapped everything together without doing any site or room planning, so it feels like I need to figure it out myself unfortunately.

Any advice?

Thanks,
Dan
View attachment 321877
photo credit: https://www.northlineexpress.com/help-pipe-install-planning.html

The setup pictured is terrible. I don't know of a stove manufacturer that would suggest coming off the flue collar with a 90º elbow like this. The through the wall thimble should have been 3 ft higher. I just emailed Northline to get this changed.

It sounds like your thimble is higher, like 2-3 ft above the stove, correct? If so, one thing that will help is eliminating the 90º elbow and replacing it with two 45s to make an offset like this middle picture.



If you can post some pictures of the inside install and also of the chimney outside, we may be able to spot other issues.
Also, if you open a nearby window or door 1/2", does that help improve the situation at all?

 

[wetwood4life]

We get smoke on reloads too, or anytime during the burn cycle. Smoke on startup is almost easier, because I can take my time loading the stove and the smoke doesn't start until I light it. Thanks for the hair dryer tip, I'll try that next time I start with a downdraft. I haven't had luck with the candle method. 30 minutes of a candle in the stove didn't help at all in the past.

Sorry for the picture, it's just one I found online that looked similar. Our setup is your "1.4: Avoid" 😢. Maybe we can upgrade to double 45s - is that a DIY job, or something that always requires a pro? I superstitiously open the front door (same room, same side of the house) 6" anytime I reload... but I'm not sure it helps much, if at all.

Inside & outside pictures attached. We're the house on the left, obviously 😄

 

[Wildflush]

I have a similar setup with a stove that has a tight corner clearance. About 3’ up then a 90 thru a wall thimble. About 23’ top of stove to top of cap. My installer said 45’s would push the stove out further from the wall and we did not want that. I have no problem getting a good draft. Definitely do the hairdryer. I do it every morning to eliminate the stack effect of cold air. Run in for 2 minutes and I have the top down ready to light. I also have a window near the stove that I crack.

 

[begreen]

Cold outside flues sometimes need warming up before they settle down. A hair dryer works for many. Some use a map torch. Changing to the 45º offset will help a little. It's not too hard using the stovepipe offset tables provided by the mfg., but it takes a little jockeying sometimes and preassembly to determine the final connecting length to the thimble.

 

[wetwood4life]

Ok, so hair dryer (or maybe a small space heater?) to help the cold starts. Any ideas about the smoky reloads? If I open the stove door more than a crack, we're getting smoke in the room. Leaving it cracked for a few minutes to resume the draft doesn't seem to work. If I put any new fuel on, even kindling, that's just more smoke/flames coming into the room.

I've gotten into my head that the chimney isn't tall enough... or that there's some problem with it stopping below the roof line, and below the main boiler chimney (the brick one on the right). Are those red flags, or should be fine?

 

[Wildflush]

On my reloads I open the air all the way than crack the door for a bit then open the door. Since I reload when there’s coals I don’t get smoke. If I open the door when there’s an active fire I have gotten a small amount of roll out at times. I do crack a window which helps. Can’t answer the technical questions. More seasoned folks can help with those.

 

[begreen]

On my reloads I open the air all the way than crack the door for a bit then open the door. Since I reload when there’s coals I don’t get smoke. If I open the door when there’s an active fire I have gotten a small amount of roll out at times. I do crack a window which helps. Can’t answer the technical questions. More seasoned folks can help with those.

Different stove and an easier breather makes a difference when the draft is marginal.

 

[BillBurns]

I use a small space heater with a blower. Its the size of the door opening, and it heats the flue up in like 5 mins, enough to get a fire going smoke free.

 

[wetwood4life]

Do you guys have problems with ash blowing back into the room while you're preheating the flue?

 

[begreen]

Do you guys have problems with ash blowing back into the room while you're preheating the flue?

Good question. I don't need to preheat, but if I did I would probably use my Harbor Freight heat gun above the baffle. That should keep ash stirring to a minimum.

 

[BillBurns]

I use mine daily basically, and it might blow a few flakes of fly ash out at start up, but thats it.

 

[Wildflush]

Do you guys have problems with ash blowing back into the room while you're preheating the flue?

No never hairdryer pointed to the inside middle front toward flue for 2 min. Works every time and no ash blowing back at me. Just did it actually since I’m late starting a fire.

Need to buy a torch since hairdryer won’t work if I lose power.

 

[wetwood4life]

Does anyone think it would help to add another 4' section to the chimney? The cold starts are just one symptom, and I'd really wish to fix this wholesale and be done with it, but don't want to go chasing changes that won't help.

 

[begreen]

Sorry to say it, but the best way to fix it wholesale is to rout the chimney pipe straight up through the house or switch to an easier breathing stove. Both are not likely to happen so switching the stove pipe to a 45 offset may be the next thing to try.

 

[wetwood4life]

Ah, I misunderstood earlier when you said breather I thought that was the chimney cap. Are Hearthstones, or the Castleton specifically tight on air? Would a Vermont Castings have been better in this respect? We considered one but ultimately chose the Hearthstone obviously.

 

[bigealta]

What's the moisture content of your wood? Inferior seasoned wood will exasperate the problem.

 

[wetwood4life]

Yeah, wood moisture isn't great, I'd call it borderline. I understand subpar wood will make more smoke, but this is a problem even with my best wood, or bone-dry kindling, even with nothing burning.

 

[Jsjac1]

My first thought when I saw the picture of the chimney was it is to short.
I think that it is supposed to be at least level with the ridge of the roof. Preferable two feet above.

 

[Wildflush]

The only way to know is to bring a few splits in the house for a few days and resplit it and use a moisture meter in the middle of the split along the grain, under 20% is where you need to be.

Warming the flue with primary air open should help on the cold start. You should not have to open the stove again until reload and coaling stage you should not get much smoke then.

 

[Wildflush]

Class A looks fine to me from pic. Minimum of 3 feet from high side of home. At least 2’ taller than anything within 10’ horizontal which would be their roof pitch.

 

[Jsjac1]

Okay, my bad. I thought it was two feet from something

 

[wetwood4life]

You know what... I forgot about the 3/2/10 rule. I don't think our chimney follows that!

I think we have a 12/12 roof (45 degree angle). So 10' horizontal clearance needs 10' vertical, plus the 2' means we need 12' from the drip edge.

Our install only has two 4' sections of chimney above the drip edge. You can just see the seams in the photos.

 

[Wildflush]

It’s hard to tell from a pic. If what your saying is correct that another 4’ plus cap would give you what you need.