Preheat flu

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tlhfirelion

Feeling the Heat
Aug 6, 2007
429
Well fellas, I’m not as seasoned as my firewood so it seems. I’ve had wood burners for years and thought I had the basics figured out. However, I just finished building our last home and have a Madison wood burner installed. This is my first burner with an OAK. It’s finally gotten cold enough to use the stove so I fired it up like I always have done in the past, and had the worst bout of smoke pushed back into the house than ever before. I had to open windows and doors, it looked like the house was in fire from the outside. Lol.
I started with a top down stack and always have a bundle of paper at the top to burn first. I assumed that was enough to preheat the flu because it’s always worked. This time, I had smoke pouring out of all kinds of openings on this stove, especially along the top and back.
I suspect this is a combo of this new stove with the OAK and my error.
What on earth did I do and how can I prevent this?
Thanks you in advance for your help.
 

Gearhead660

Minister of Fire
Dec 20, 2018
690
Southern WI
Pics of set up could help. I have heard people use a propane torch to help establish draft before starting a fire.
 

nola mike

Minister of Fire
Sep 13, 2010
840
Richmond/Montross, Virginia
This happens to me occasionally when I return to a cold (like low 50's) house after several days away. I have a very tall chimney, suspect that the dense air in the stack means the path of least resistance is back into the house. I have found that opening windows does nothing in this situation. It takes a while to preheat. Torch works, but I've found a hairdryer is best. Candles can also work but take forever.
 
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Sawset

Minister of Fire
Feb 14, 2015
1,200
Palmyra, WI
It’s finally gotten cold enough to use the stove
How cold is cold enough. You have a crawl space - warmer climate? If it's in the 50s or above here, startup can be iffy sometimes depending on outside conditions - humidity, air pressure, wind etc.
 
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brazilbl

Burning Hunk
Aug 24, 2017
115
El Dorado County, CA
Used a butane torch and later on (based on a tip from a user here) and used a heat gun to heat up the flue when this happened in my setup.
 
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Woodsplitter67

Minister of Fire
Jan 19, 2017
1,957
Woolwich nj
A slight description of the set up will help as well as what you consider cold enough. information is a good starting point.

My stove drafts well in cooler temperatures, but that being said if the outside temp is in the 50s and I have a cold stove I'll need 2 to 3 sheets of paper to establish good draft because the inside house temp may be in the mid to low 60s so there's not much of a temp difference between inside and outside temperature.

If its colder outside say in the low 30s and my inside temp is in the low to mid 60s and the stove is cold its like 1 to 1.5 sheets of newspaper. The difference between inside and outside temperatures are 30 degrees, so establishing draft is easier. I don't ball up my paper very hard.. I keep it loose. You may want to put in 4 sheets light 2 and light your kindling and then light the other 2 when you get the kindling going.. but give us some solid info so we can give the best advice to help you..
 
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tlhfirelion

Feeling the Heat
Aug 6, 2007
429
Pics of set up could help. I have heard people use a propane torch to help establish draft before starting a fire.
7B318C79-18DF-49EE-8F80-FBF1CADF5FCE.jpeg
not sure what types of pics you need, but this is one I have already taken. Note, there is no damper, I just had that metal sign and stuck it on the stove for character. The OAK runs out the wall to the left. We are on a crawlspace. The temps the day I had the most trouble was approx. 39 degrees that morning outside. I do use a propane torch to light the stove so I could try using it to preheat. Thank you.
 

tlhfirelion

Feeling the Heat
Aug 6, 2007
429
This happens to me occasionally when I return to a cold (like low 50's) house after several days away. I have a very tall chimney, suspect that the dense air in the stack means the path of least resistance is back into the house. I have found that opening windows does nothing in this situation. It takes a while to preheat. Torch works, but I've found a hairdryer is best. Candles can also work but take forever.
Im usually up pretty early and would wake the house if I tried using a hairdryer to heat the flu. Lol. how tall is your chimney?
 

tlhfirelion

Feeling the Heat
Aug 6, 2007
429
A slight description of the set up will help as well as what you consider cold enough. information is a good starting point.

My stove drafts well in cooler temperatures, but that being said if the outside temp is in the 50s and I have a cold stove I'll need 2 to 3 sheets of paper to establish good draft because the inside house temp may be in the mid to low 60s so there's not much of a temp difference between inside and outside temperature.

If its colder outside say in the low 30s and my inside temp is in the low to mid 60s and the stove is cold its like 1 to 1.5 sheets of newspaper. The difference between inside and outside temperatures are 30 degrees, so establishing draft is easier. I don't ball up my paper very hard.. I keep it loose. You may want to put in 4 sheets light 2 and light your kindling and then light the other 2 when you get the kindling going.. but give us some solid info so we can give the best advice to help you..

As far as description goes, it’s a single wall interior pipe including exterior pipe, the total stack is 15’ tall. Madison stove, with OAK. I’ve had a few small break in fires with zero issue. It was when I went for a big fire that the issues started.
ive used the newspaper route many times before and it always worked well but this time it didn’t so wasn’t sure what the heck went wrong.
 

kennyp2339

Minister of Fire
Feb 16, 2014
5,924
07462
I'm not to familiar with the madison specifically, but was that spring assist air control open for lighting the stove? I tried looking up the OAK instructions but couldnt find any online, dumb question here, is there a OAK plate that needs to be removed on the stove for the proper primary air route?
 
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tlhfirelion

Feeling the Heat
Aug 6, 2007
429
I'm not to familiar with the madison specifically, but was that spring assist air control open for lighting the stove? I tried looking up the OAK instructions but couldnt find any online, dumb question here, is there a OAK plate that needs to be removed on the stove for the proper primary air route?

truth be told, I didn’t even look to see if there is an OAK plate, lol, man I feel like a heel. I’ll look shortly and find out. I wouldn’t be surprised if it’s there blocking all that wonderful outside air. I installed this stove in stages along with a lot of other things when building the house, and removed it once after changing the hearth pad to the one piece blackened steel you see in the pic.
I may have been too busy patting myself on the back when the house was done and forgot to check the oak set up correctly.

If I had one gripe on this stove, it’s the air control and spring assist. I’m not a fan as it seems gimmicky to me. Maybe that’s just because it’s new to me but still.
 

moresnow

Minister of Fire
Jan 13, 2015
1,780
Iowa
Was there any indoor appliance fan operating/competing for indoor air at the time? Clothes dryer running? Bath fan, range hood fan, HRV etc? Betting the new house is very tight as well. Might be worth a look at the entire OAK setup to be sure something isn't awry.
 
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tlhfirelion

Feeling the Heat
Aug 6, 2007
429
Was there any indoor appliance fan operating/competing for indoor air at the time? Clothes dryer running? Bath fan, range hood fan, HRV etc? Betting the new house is very tight as well. Might be worth a look at the entire OAK setup to be sure something isn't awry.
Yes it is very air tight. It’s a Nudura ICF house. It does have an ERV and that runs most of the time. Other than that, no other fans or anything running. I agree, I do need to take a look at the whole oak system.
thanks for everyone’s helpful replies. I’ll report back when I look at the oak.
 

Woodsplitter67

Minister of Fire
Jan 19, 2017
1,957
Woolwich nj
As far as description goes, it’s a single wall interior pipe including exterior pipe, the total stack is 15’ tall. Madison stove, with OAK. I’ve had a few small break in fires with zero issue. It was when I went for a big fire that the issues started.
ive used the newspaper route many times before and it always worked well but this time it didn’t so wasn’t sure what the heck went wrong.
did this happen on a cold start or were you on any type of a reload with a secondary closed
 
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Rickb

Minister of Fire
Oct 24, 2012
1,139
St.Louis
Mine back drafts cold about 30% of the time. I just use my small tourch I use to start the fire and aim it up the flue for about 10 seconds first. usually takes care of it.
 
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tlhfirelion

Feeling the Heat
Aug 6, 2007
429
Well it looks like there is no plate blocking my OAK on the back of the stove. Or I don’t think so. I took the flexible pipe off and looked inside. The hole goes in about 2” and there is metal there but it seems more like a channel. I can stick my finger up and in the area around the inside of the inlet. So doesn’t seem like a cut off plate if that makes sense. Is that installed correctly or so o need to do something to fix an issue? Thank you.
 

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MTY

Feeling the Heat
Jan 9, 2019
487
Idaho
At the last house I had an outside masonry chimney. I took one sheet of newspaper. twisted it length ways, stuffed it up the pipe, laid the fire, lit the paper in the pipe and then paper in the kindling. This will only work if you do not have a baffle. The stove at that house was an old Earthstove.
 
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tlhfirelion

Feeling the Heat
Aug 6, 2007
429
It could be that you have a negative pressure situation because of your ERV .
I was under the impression that the oak was the solution for that.

I preheated the flu last night and the fire ran great. Woke up to a nice bed of coals and a warm house. Thanks for everyone’s help!
 

tabner

Burning Hunk
Jan 17, 2019
170
Eastern CT
For people who deal with the cold stack / negative pressure / pre heating requirements - roughly how long do you have to preheat the flue, and with what method? I see a candle for 15 mins posted above. Wondering about hair dryers and torches?
I just played around and tried a tiny first fire in my new setup. but my basement is very cold - heat pump water heater brings temp down about 6 degrees. outside was mid 60s, inside was probably mid 50s. Tried a couple sheets of newspaper, a candle for about 2 mins, and a hair dryer for about 2 mins, never could get it flowing the right way. I ran out of time and had to give up. My chimney is 27 feet up, interior, but I do have a 90 degree above the stove (and then the other 90 to go up the chimney).
I'm thinking I'm just going to have a generally difficult setup to cold start, and once i have colder outside temps it'll be fine, i'll probably just have to get used to some serious preheating for cold starts. I'm just wondering what i should expect that preheating to look like - 3 minutes with a hair dryer, 30 mins with a space heater, etc?
 

Highbeam

Minister of Fire
Dec 28, 2006
19,140
Mt. Rainier Foothills, WA
For people who deal with the cold stack / negative pressure / pre heating requirements - roughly how long do you have to preheat the flue, and with what method? I see a candle for 15 mins posted above. Wondering about hair dryers and torches?
I just played around and tried a tiny first fire in my new setup. but my basement is very cold - heat pump water heater brings temp down about 6 degrees. outside was mid 60s, inside was probably mid 50s. Tried a couple sheets of newspaper, a candle for about 2 mins, and a hair dryer for about 2 mins, never could get it flowing the right way. I ran out of time and had to give up. My chimney is 27 feet up, interior, but I do have a 90 degree above the stove (and then the other 90 to go up the chimney).
I'm thinking I'm just going to have a generally difficult setup to cold start, and once i have colder outside temps it'll be fine, i'll probably just have to get used to some serious preheating for cold starts. I'm just wondering what i should expect that preheating to look like - 3 minutes with a hair dryer, 30 mins with a space heater, etc?
Forget the hair dryer, preheat with one of these and then use it to start the fire.

Everything seems to work better as the outside temperature cools but basement installs often have problems.
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