Wood stove installed in fireplace flue

[fordmann89]

I’d like to start off that I am new to the forum here as well wood stoves. I’d like to give a short introduction of myself for anyone interested. I’m from E Tennessee, a father to two boys, a husband to a wonderful woman, and most importantly a follower of Jesus Christ. This May will be my 10 year mark in the Air Force. I love doing my own work when able to, save a little money on labor, and enjoy to learn new things.

Now to the good stuff. We purchased a home a few months ago. Two story house with an unfinished basement. Main level is where we mostly stay. The boys have a play room up on the second level. Main level and second level have separate central heat and air units. Main level is roughly 2400 sqft and second level is roughly 1100 sqft. We have a fireplace on the main floor in the living room and a fireplace in the basement. Both have a 8”x12” flue if I’m not mistaken. In the basement we have a Englander 28-3500 add on furnace that is plumbed into the main and second level furnaces. It has roughly 3’ of 6 pipe coming out vertically, 90 elbow into about 2’ into the basement fireplace flue. I’ve read up a bit on how to get a good bed of coals, and load the stove then turn the draft controls down for a slow burn. My biggest question and it may be silly, but does the damper on the fireplace that the stove vents to need to be opened or closed? I’ve been opening it when burning but not so sure if I should be doing so. The thermostat for the fan is set at 85 off, 140 on, and 200 limit open. If anyone has any advice/input on the specific make/model or burning wood in general I would greatly appreciate it. Thanks!

 

[Gearhead660]

So the add on furnace just goes into the fireplace flue and not piped all the way up? If that's the case, it's needs to be corrected asap.

 

[Socratic Monologue]

Page 3 of the Englander manual: "DO NOT CONNECT THIS UNIT TO A CHIMNEY FLUE SERVING ANOTHER
APPLIANCE. " (Caps and underlining in original)

Englander 3,000 sq. ft. Wood-Burning Add-On Furnace : Use and Care Manual : Page 3

Find and download user guides and product manuals

www.manualshelf.com

 

[fordmann89]

Gearhead, yes that is correct. It plumbs straight into the the flue as the fireplace.

Yes I saw the manual and where it stated that. I’m not a professional when it comes to fireplaces and such. However without detailed explanation in the manual I took it as you shouldn’t “use” two appliances sharing the same flue. As far as I’m concerned that fireplace in the unfinished basement doesn’t exist. It hasn’t been used, the previous owner told me he never used it either. He told me he burned wood in the stove plumbed as it is for years.

Now would either of you two mind explaining why it shouldn’t be plumbed the way it is? I’m not trying to argue, but better understand all of this. I loaded it with hickory and oak last night and it burned from 2200-0400 and had a nice bed of hot embers this morning. We haven’t had any issues with it and it helped heat the house last night very well while it was in the teens.

Thanks for the help!

 

[Socratic Monologue]

I'm not a pro either, so I lean on the methods established by code, by the manufacturer, and by general consensus here unless I have done a lot of research to weigh the pros and cons of deviating from those methods.

My understanding is that under certain combinations of common but unpredictable conditions and combinations of conditions (wind, flue temps, reduced draft caused by moderate outside temps, a fire that smolders because of improper adjustment or wet wood or a mechanical issue with the furnace or an animal lodged in the flue or creosote buildup, air flow into and out of the house (from bath fans, other woodburners, open windows, branch falling through a window in a storm, etc, etc, etc) a backdraft -- air moving down the flue instead of up -- can occur. This is more likely in a basement installation than in a ground-level installation, from what I read here.

Anyway, if a backdraft does occur, the house can fill with CO and smoke, either of which can and have killed many a family. Basically, with a 2 foot stub of pipe up the flue, you are emptying the furnace into your living space and hoping the gases will rise. This is all much, much less likely if the flue gases are vented outside the living area, i.e. three feet above the roof line.

Woodburning safety isn't a matter of doing what works now, it is a matter of setting things up so that under all unpredictable future circumstances, safety is preserved as much as is possible. A proper venting arrangement is like a seat belt in a car -- you don't need it until you do.

 

[Gearhead660]

I'm not a pro either, so I lean on the methods established by code, by the manufacturer, and by general consensus here unless I have done a lot of research to weigh the pros and cons of deviating from those methods.

My understanding is that under certain combinations of common but unpredictable conditions and combinations of conditions (wind, flue temps, reduced draft caused by moderate outside temps, a fire that smolders because of improper adjustment or wet wood or a mechanical issue with the furnace or an animal lodged in the flue or creosote buildup, air flow into and out of the house (from bath fans, other woodburners, open windows, branch falling through a window in a storm, etc, etc, etc) a backdraft -- air moving down the flue instead of up -- can occur. This is more likely in a basement installation than in a ground-level installation, from what I read here.

Anyway, if a backdraft does occur, the house can fill with CO and smoke, either of which can and have killed many a family. Basically, with a 2 foot stub of pipe up the flue, you are emptying the furnace into your living space and hoping the gases will rise. This is all much, much less likely if the flue gases are vented outside the living area, i.e. three feet above the roof line.

Woodburning safety isn't a matter of doing what works now, it is a matter of setting things up so that under all unpredictable future circumstances, safety is preserved as much as is possible. A proper venting arrangement is like a seat belt in a car -- you don't need it until you do.

It all comes down to safety. It may work, but its not safe.

 

[bholler]

Gearhead, yes that is correct. It plumbs straight into the the flue as the fireplace.

Yes I saw the manual and where it stated that. I’m not a professional when it comes to fireplaces and such. However without detailed explanation in the manual I took it as you shouldn’t “use” two appliances sharing the same flue. As far as I’m concerned that fireplace in the unfinished basement doesn’t exist. It hasn’t been used, the previous owner told me he never used it either. He told me he burned wood in the stove plumbed as it is for years.

Now would either of you two mind explaining why it shouldn’t be plumbed the way it is? I’m not trying to argue, but better understand all of this. I loaded it with hickory and oak last night and it burned from 2200-0400 and had a nice bed of hot embers this morning. We haven’t had any issues with it and it helped heat the house last night very well while it was in the teens.

Thanks for the help!

You need to install a full insulated liner from the top of the chimney to a tee in the fireplace. Before that you need to clean the entire chimney and smoke chamber very well. The furnace will never work properly as is and it is pretty unsafe

 

[TWilk117]

You need to install a full insulated liner from the top of the chimney to a tee in the fireplace. Before that you need to clean the entire chimney and smoke chamber very well. The furnace will never work properly as is and it is pretty unsafe

Bholler,

I am curious why a T with a clean out is used inside a masonry wall? Wouldn’t that be difficult to actually get to and clean out?
I’m asking here as I am installing a 28-4000 in a similar way to the OP. Only I have ordered a 20 ft insulated liner.

 

[bholler]

Bholler,

I am curious why a T with a clean out is used inside a masonry wall? Wouldn’t that be difficult to actually get to and clean out?
I’m asking here as I am installing a 28-4000 in a similar way to the OP. Only I have ordered a 20 ft insulated liner.

Because if you just curve the liner out anything that falls down will restrict it

 

[TWilk117]

Thanks.