Fireplace stove venting, what not to do.

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VCBurner

Minister of Fire
Jan 2, 2010
1,509
Templeton, MA
I just wanted to share my experiences on this topic. I hooked up my DW up to a fireplace back in November. Upon inspection, the fireplace was very clean. Despite having burned a cord in it as a fireplace in the winter of 07/08 and having a cast iron box stove in there for the winters of 08/09 and 09/10. The box stove did not add any measurable amount of build up due to having no baffles or dampers and burning wide open with a non airtight n/s design. I used the fireplace damper to regulate the fire and it worked really well in this way. However, it was unable to heat 1000 sq ft by itself. It could keep the upstairs in the 60's with an occasional 70's peak while chewing a lot of wood! During really low temps it struggled to keep the house comfortable. I ended up with a stove in the basement to take care of the bulk of the heating. The old Surdiac was a pretty good pre EPA sotve but it had short burn times and a tiny firebox. In February of 2010 I bought a rebuilt DW. It was originally intended for the basement, which was unfinished. The stove is rated to heat up to 1600 sq ft. But the entire space being heated was 1750 sq ft from an unfinished basement. It was a tall order for any mid sized stove in the coldest part of the winter. So the decision was made to put the stove upstairs this fall.

This is where my biggest mistake was made. I hooked it up to a block off plate with nothing above to extend to the tile lined part of the chimney. The whole on the block off plate was in the center of it , but it was not lining up with the chimney. It was too far forward. Adding to the trouble was the fireplace damper, which was so helpful wiht the old non-airtight box stove. It served as a trap for anything that would fall in there from the outside. As I stated in the first paragraph, the chimney looked really clean but what was behind the damper plate on the smoke shelf went undetected. So I recently decided to move the block off plate to see how the chimney looked. The tile lined of the chimney was pretty clean! But, the smoke chamber was full of build up. About 3/16" as an average of mixed glossy and ash like build up. What surprised me the most was what I found behind the damper. There were a couple of leaves and a pine cone as well as about three quarts of debris that had gone undetected during my inspection of the chimney. I'm glad I decided to thoroughly check the entire chimney. I removed the damper plate, after brushing it in place, by simply removing a cotter pin and lifting the entire thing out. I was only able to touch what was there after removing the damper. I brushed as much debris away from the shelf with gloves hands, then vacummed out the remaider. This to me was a major hazzard that went undetected to my untrained eye for nearly four years. I'm glad that I decided to really clean the entire thing and also add a length of pipe from the block off plate to the tile lined part of the chimney. This meant a 4.5 foot section of pipe extending above the plate. I plan on relining the entire chimney with a flex pipe by the next burning season, with a cap on top, to prevent anything from falling in there. I feel my experience needed to be shared here. It may help pinpoint problems with other's set ups. Beware of the smoke shelf in your tile lined chimney, it can be a major fire hazzard!


Here are some pictures showing the dirty smoke chaimber before the damper was taken off and pics of the final re-vamp with an added pipe and moved whole on the block off plate.

1. Old block off plate with 90 attached, this is the face that would have been visible if looking up into the fireplace.
2. Looking up the fireplace before clean up, damper still there, you can see the runny build up that had dried up to the touch, as well as build up on the slanted part of the fireplace at the bottom of the picture. The huge smoke chamber with build up. It was four feet up into the tile lined portion!
3. Looking up with damper shut. Yuck!
4. This is what the stove was hooked up to with nothing up top. It's surprising that the stove even drafted like this!
5. This is looking up into the fireplace and up the newly offset section of 4.5' pipe. It is in the fireplace.
6. Looking into the fireplace with the improved set up in place. Newly reset pipe whole and see up th 4.5' section of pipe. This was at night so you can't see daylight.
7. A new 90 in place to replace the old rusty one that was there before. Ready for the stove!

There's still a lot of room for improvement. But this is a step in the right direction and complies with the owners manual. It will eventually have a full 6" liner, cap and insullation all the way up.
 

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Good information to remember. I'm sure with a new correct sized full length liner you'll get better draft and not have nearly the amount of creosote.
 
That 4.5 foot piece is silver - is it a section of stainless single wall stove pipe, or is it a piece of galvanized heating duct?
 
That sure looks like galvanized pipe there, I hope not, In fact anything from the block-off plate up should be Stainless Steel. Looks like a step in the right direction though, nice looking work.
 
Good eye guys! Yeah, the pipe was something that was sitting in my FIL's shed. It was a 5' piece of pipe, which I hope was unpainted white stove pipe. The truth is I don't know! Probably is galvy. Funny you guys picked up on it because I was aware of the galvinized fumes. If it is galvy, I'm hoping that any fumes will go up the chimney with the rest of the gasses since it has no top plate or SS liner beyond the tile liners. But, here's a quote I have questioned in the past from hearth.com's main info articles:

Materials needed
Sheet metal - 24 or 26 gauge galvanized metal is ideal for this application - available at many plumbing and heating supply houses

It came from this main article page:
https://www.hearth.com/econtent/index.php/articles/making_a_block_off_plate/

Good lookin out, though!

Chris
 
Galvanised is fine for a block off plate, but not for a stove pipe. That pipe can get mighty hot and will carry some wicked corrosive gasses. A black or stainless stove pipe is thick enough and durable enough to withstand the conditions. Galvanised? Not so much ...

You should be able to get 5 feet of black stove pipe for $20 and single wall stainless for about triple that at your local home center. That would be highly recommended!
 
FixedGearFlyer said:
Galvanised is fine for a block off plate, but not for a stove pipe. That pipe can get mighty hot and will carry some wicked corrosive gasses. A black or stainless stove pipe is thick enough and durable enough to withstand the conditions. Galvanised? Not so much ...

You should be able to get 5 feet of black stove pipe for $20 and single wall stainless for about triple that at your local home center. That would be highly recommended!
Thanks FGF, will do! Sounds like an easy fix.
 
I realize it is a hazzardous practice and intend on fixing the problem. But, considering the pipe is not exposed in the house and is going up from the block off plate inside the chimney, which has no top plate. So, it just goes straight up the chimney and never has a chance to get inside the house. BTW, I asked my FIL and he said he didn't know if it was plain tin or galvinized, so it may not even be galvy. Funny, I posted a thread on what not to do and may still be using something in that category. :red:
 
My wife moved here a few months before I did, and her grandma bought her the Englander. The non-expert that installed it just put a block-off plate over the fireplace opening, with black pipe coming out the back of the stove and through the plate. You probably have a pretty good idea of what happened next; Huge build-up of volatile gasses in the fireplace and smoke chamber. Wife opened the stove door, supplying the necessary oxygen to ignite an explosion that blew the door out of her hand and knocked her on her butt. She then called her cousin, who was working as a sweep at the time. She told my wife "Oh, no, you can't do it that way!" :lol:
 
Good to hear that there was no fire from this badly rigged installation. Why take this kind of risk inside the home? Is this a tile-lined chimney? Why is there no full liner on this stove?
 
BeGreen said:
Good to hear that there was no fire from this badly rigged installation. Thanks BG, I'm glad there wasn't a fire here too! Why take this kind of risk inside the home? This was a post on what not to do to install a stove! The only thing missing to become compliant with the manual instructions was a pipe going into the tile lined section of the chimney. The whole on the block off plate needed to be moved to line up with the chimney better.Is this a tile-lined chimney? YES. But the smoke chamber was almost four feet tall. Then the tile liners begin. The new pipe extends just beyond the first tile. Why is there no full liner on this stove?It is completely legal and safe to have a pipe going into the tile lined portion of a chimney. It is up to the owner to chose which way to go. Due to lack of money I decided to line later.

BeGreen, I posted this thread hoping that I could show others not to hook up their stoves directly into the block off plate without having a pipe into the tile lined portion of a masonry chimney.. The result as you can see, is a messy creosote build up. I realized the inefficient venting set up I created. I explained to you on another thread what my situation is. Furthermore, I intend to purchase a liner and install it in this chimney. But, let's not forget, it is still legal here in this state and many others not to have a full liner in your masonry chimney while operating a stove!

That said, I agree that lining it will create an ideal burning situation. I will continue to improve the set up with a full liner as soon as the money is available. For now, the improvements I made to the chimney set up will be another step in the right direction. Achieving perfection will continue to be a goal.
 
....is legal in MA, as long as it also complies with certain flue liner:flue collar sizing requirements - either 2:1 or 3:1.

Of course, if your local building inspector OK's it, you're good to go!
 
Thanks for clearing this up. There was a concern that this was an unlined chimney. Good to hear a stainless liner is on it's way. If I lived closer, I'd be glad to help you out with it.
 
BeGreen said:
Thanks for clearing this up. There was a concern that this was an unlined chimney. Good to hear a stainless liner is on it's way. If I lived closer, I'd be glad to help you out with it.
Thanks brother, I know all the people here care about each other and are always looking to lend a hand and give good advice. It just shows what kind of community this is. I'll update this post when I get the liner and put up some pics of the install. It'll make me happy to have the set up greatly improved.
 
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