33’ (10m) pellet stove flue advice

[australisblue]

Hello, I’m looking at running a pellet stove flue up an old 33’ (10m) tall chimney. Any tips for one of this length? I was assuming 4” (100mm) stainless flexible flue to get past one bend in the chimney.

I’ve read some older posts that others have done similar lengths apparently without issue. Should one of this length be insulated to keep the gases hotter to help with the draw? I know a fan is used in pellet stoves but it’s my understanding there still needs to be some draw to help with longer lengths. I can go a larger diameter but not really sure what would be optimal.

The fireplace is large and a freestanding heater would sit in it nicely and so I think other than perhaps a T fitting on the back of the stove, the entire 33’ length would be vertical (other than the slight bend).

Thanks for any thoughts (or reassurance)!

 

[australisblue]

Any thoughts? Would 4” work or would 5” be better for the height (I know an unusual size for a pellet stove)? Insulated or not?

Someone here must have a chimney as tall with a pellet stove.. I can experiment but would rather a good starting point to avoid wasting too much time and money.

Thank you

 

[bholler]

Any thoughts? Would 4” work or would 5” be better for the height (I know an unusual size for a pellet stove)? Insulated or not?

Someone here must have a chimney as tall with a pellet stove.. I can experiment but would rather a good starting point to avoid wasting too much time and money.

Thank you

Ask the stove manufacturer

 

[australisblue]

Ask the stove manufacturer

Unfortunately most of the range where I live are generic units imported, it’s not quite as easy as just asking the manufacturer and the staff at the store are very unhelpful (there’s literally one store I can find in my area that even sells pellet stoves too).

I’m trying to find an independent installer to ask for advice but that’s not easy either. I am asking here as having some input from someone who actually has a similar install would be useful.

 

[bholler]

Unfortunately most of the range where I live are generic units imported, it’s not quite as easy as just asking the manufacturer and the staff at the store are very unhelpful (there’s literally one store I can find in my area that even sells pellet stoves too).

I’m trying to find an independent installer to ask for advice but that’s not easy either. I am asking here as having some input from someone who actually has a similar install would be useful.

There has to be a manufacturer. And there has to be install specs. If you can't contact the manufacturer how will you ever get parts or diagnose issues

 

[australisblue]

There has to be a manufacturer. And there has to be install specs. If you can't contact the manufacturer how will you ever get parts or diagnose issues

Of course there is a manufacturer, but locating a Chinese manufacturer and expecting to get some help direct from them about installation is a stretch. I had actually previously located (after a lot of searching) the factory I think produce them, they are sold under a local name here, not the name of a factory that produces generic units, my message to them had gone unanswered so far, they aren’t a place that is likely to deal with end consumer/installation questions so I’m not holding my breath. The local store handles warranty repairs and parts (store has been there at least 15 years so I am happy to take a risk). Despite the origins the construction seems good, I don’t have the luxury of picking a more well known brand here, this is basically the only unit available here that will fit my requirements and the space it needs to go into.

I have done some work trying to find info before posting a question here, I am still keen to find someone here with a similar installation in terms of chimney height to hear their experiences. Thanks.

 

[bholler]

Of course there is a manufacturer, but locating a Chinese manufacturer and expecting to get some help direct from them about installation is a stretch. I had actually previously located (after a lot of searching) the factory I think produce them, they are sold under a local name here, not the name of a factory that produces generic units, my message to them had gone unanswered so far, they aren’t a place that is likely to deal with end consumer/installation questions so I’m not holding my breath. The local store handles warranty repairs and parts (store has been there at least 15 years so I am happy to take a risk). Despite the origins the construction seems good, I don’t have the luxury of picking a more well known brand here, this is basically the only unit available here that will fit my requirements and the space it needs to go into.

I have done some work trying to find info before posting a question here, I am still keen to find someone here with a similar installation in terms of chimney height to hear their experiences. Thanks.

The problem is every stove is different. I have installed some stoves that work fine at that height others absolutely will not. Some require larger liners as height goes up others don't.

 

[australisblue]

The problem is every stove is different. I have installed some stoves that work fine at that height others absolutely will not. Some require larger liners as height goes up others don't.

Thank you. I know each stove is different but I’d love to hear your experiences about those that did and didn’t work alike. In the ones that tall that have worked, what pipe was run? 4” plain (ie not insulated pipe?). And the ones that wouldn’t work, was it possible to them to work with an unusual install, like larger than 5” or insulating the flue? Or running a shorter 4” from the stove and going into a larger 5” or 6” for most of the chimney?

One option I can do is running a larger 6” down the straight section of the chimney (bend is near the bottom) and running a shorter 4” from the stove to feed into that..

 

[bholler]

Thank you. I know each stove is different but I’d love to hear your experiences about those that did and didn’t work alike. In the ones that tall that have worked, what pipe was run? 4” plain (ie not insulated pipe?). And the ones that wouldn’t work, was it possible to them to work with an unusual install, like larger than 5” or insulating the flue? Or running a shorter 4” from the stove and going into a larger 5” or 6” for most of the chimney?

One option I can do is running a larger 6” down the straight section of the chimney (bend is near the bottom) and running a shorter 4” from the stove to feed into that..

I follow manufacturers instructions. As I said some require larger some smaller. Some can be adjusted better to account for higher natural draft and some will simply overfire with that much draft. And I insulate every liner I install

 

[australisblue]

I follow manufacturers instructions. As I said some require larger some smaller. Some can be adjusted better to account for higher natural draft and some will simply overfire with that much draft. And I insulate every liner I install

What’s the smallest and largest you run? Is it more likely the height will cause too much draw vs not enough? Say you had a random pellet stove you didn’t know much about, 8kw (~30,000 BTU), what would be a good starting point given the lack of info.. and then in your experience if it’s over drafting or under drafting, what would you adjust to compensate? I can experiment but if someone with a lot of experience could offer a reasonable starting point and then what to try adjusting depending on how it was performing would be super helpful.

The store is unhelpful, my install is outside of what they do 99% of the time and so kind of don’t want to work a solution for me as I think they are worried if it doesn’t work they have to spend money trying to fix it..

We’ve looked at other heating options but these would be perfect and bring back the look of a fire into old fire places. I have a cold family that can do with your expertise lol

 

[bholler]

What’s the smallest and largest you run? Is it more likely the height will cause too much draw vs not enough? Say you had a random pellet stove you didn’t know much about, 8kw (~30,000 BTU), what would be a good starting point given the lack of info.. and then in your experience if it’s over drafting or under drafting, what would you adjust to compensate? I can experiment but if someone with a lot of experience could offer a reasonable starting point and then what to try adjusting depending on how it was performing would be super helpful.

The store is unhelpful, my install is outside of what they do 99% of the time and so kind of don’t want to work a solution for me as I think they are worried if it doesn’t work they have to spend money trying to fix it..

We’ve looked at other heating options but these would be perfect and bring back the look of a fire into old fire places. I have a cold family that can do with your expertise lol

If there is a random pellet stove with no manufacturers instructions I won't work on it because once I touch it I am responsible for it. And with a pellet stove you really need guidance from the manufacturer.

 

[johneh]

My stove has a 4inch pipe from the stove up 6 feet to a 6 in class A chimney
which is 24 ft in height. I have run my stove for 20 years with this setup
and never had a problem. Draft on a pellet stove is not as critical as a wood
burner as the draft is a forced draft (by the combustion fan) You really only
need a natural draft during a power outage and only till the fire goes out
I Hope this helps.

 

[australisblue]

If there is a random pellet stove with no manufacturers instructions I won't work on it because once I touch it I am responsible for it. And with a pellet stove you really need guidance from the manufacturer.

Yeah sure, and you won’t be responsible. But say you had to, the government has you locked in a room with agents demanding to know your secrets about pellet stove installations, you must have an idea where to start to get them off your case? I can say they install these to 6-7m (19-23 feet) using 4” with no problem and I suspect they use uninsulated. The guy in the store was suggesting the issue with taller ones was they restricted the flow too much.. he just looked at me blankly when I asked if insulated pipe or larger would help. All he said was “People don’t usually have chimneys as tall as you…”

 

[australisblue]

My stove has a 4inch pipe from the stove up 6 feet to a 6 in class A chimney
which is 24 ft in height. I have run my stove for 20 years with this setup
and never had a problem. Draft on a pellet stove is not as critical as a wood
burner as the draft is a forced draft (by the combustion fan) You really only
need a natural draft during a power outage and only till the fire goes out
I Hope this helps.

Thank you, so to clarify, the 4” has a sealed fit onto 6” flue? This is one of the options I’ve been considering trying.

 

[bholler]

My stove has a 4inch pipe from the stove up 6 feet to a 6 in class A chimney
which is 24 ft in height. I have run my stove for 20 years with this setup
and never had a problem. Draft on a pellet stove is not as critical as a wood
burner as the draft is a forced draft (by the combustion fan) You really only
need a natural draft during a power outage and only till the fire goes out
I Hope this helps.

Very true but with exceptionally tall chimneys that natural draft can be to high causing the stove to over draft.

Some stoves can easily be adjusted for that others can't.

 

[bholler]

Yeah sure, and you won’t be responsible. But say you had to, the government has you locked in a room with agents demanding to know your secrets about pellet stove installations, you must have an idea where to start to get them off your case? I can say they install these to 6-7m (19-23 feet) using 4” with no problem and I suspect they use uninsulated. The guy in the store was suggesting the issue with taller ones was they restricted the flow too much.. he just looked at me blankly when I asked if insulated pipe or larger would help. All he said was “People don’t usually have chimneys as tall as you…”

The guy in the store is only accounting for half the issue. On startup when there is no natural draft yes a tall flue can cause some smoking because the fan can't push hard enough to overcome that resistance. But once there is some heat in the chimney you may have the opposite issue with the chimney pulling to hard.

 

[australisblue]

The guy in the store is only accounting for half the issue. On startup when there is no natural draft yes a tall flue can cause some smoking because the fan can't push hard enough to overcome that resistance. But once there is some heat in the chimney you may have the opposite issue with the chimney pulling to hard.

A shorter 4” into an uninsulated 6” would reduce the initial resistance and being larger and uninsulated would mean the gases would cool more and not create as much draw once it was up and running?

I think you’re still treating this like talking to a customer who’s installation you don’t want to be your responsibility to fix if it doesn’t work so don’t really want to suggest any specific thing you would try first and what you’d try next depending on the issue, only after some ideas to try and the responsibility is all mine I appreciate your time.

 

[bholler]

A shorter 4” into an uninsulated 6” would reduce the initial resistance and being larger and uninsulated would mean the gases would cool more and not create as much draw once it was up and running?

I think you’re still treating this like talking to a customer who’s installation you don’t want to be your responsibility to fix if it doesn’t work so don’t really want to suggest any specific thing you would try first and what you’d try next depending on the issue, only after some ideas to try and the responsibility is all mine I appreciate your time.

Or the larger volume of air is going to be harder to move and take longer to heat up both because of the volume and the fact it's uninsulated. Have you read through the installation instructions in the manual? Every manufacturer I have worked with has done this testing and supplies a size vs height chart. And they can vary allot from one stove to the next. This isn't me not being willing to give you suggestions. It is me telling you there is no set answer to your question. The answer is going to vary greatly depending on the stove. Why not just vent out the side?

 

[australisblue]

Or the larger volume of air is going to be harder to move and take longer to heat up both because of the volume and the fact it's uninsulated. Have you read through the installation instructions in the manual? Every manufacturer I have worked with has done this testing and supplies a size vs height chart. And they can vary allot from one stove to the next. This isn't me not being willing to give you suggestions. It is me telling you there is no set answer to your question. The answer is going to vary greatly depending on the stove. Why not just vent out the side?

I wish I had the installation manual but I don’t. I’m trying to do as much work as I can up front to see what solutions there are to make it work, as I’m sure there is a way to get it working acceptably. It might just work with 4” all the way and I’m done. To get the manual I pretty much need to buy one and take the risk which I’m willing to do but I am weighing the risks first by asking for others experience.

A larger pipe doesn’t mean moving more air, it’s the same volume of air being move but at a lower speed and so less resistance.. (maybe I should say the same flow rate cfm type thing).

I’ll try find other installers locally and see what they say and probably take the risk on making it work and can post results back here if I do.

 

[bholler]

I wish I had the installation manual but I don’t. I’m trying to do as much work as I can up front to see what solutions there are to make it work, as I’m sure there is a way to get it working acceptably. It might just work with 4” all the way and I’m done. To get the manual I pretty much need to buy one and take the risk which I’m willing to do but I am weighing the risks first by asking for others experience.

A larger pipe doesn’t mean moving more air, it’s the same volume of air being move but at a lower speed and so less resistance..

I’ll try find other installers locally and see what they say and probably take the risk on making it work and can post results back here if I do.

The larger pipe has more volume. That air on start up is going to be cold and take more energy to get moving up and out of the chimney.

If the store wants to sell you a stove tell them you need to see the manual. Or look up the model number online to get a copy of it.

Again why not side vent and avoid the whole issue with the tall chimney.

Btw I have read plenty of manual that clearly say do not install with more that a set height chimney.

 

[australisblue]

Side venting is not an option, the wall the fireplace backs onto is internal, the house is 130 year old heritage listed, if you saw the room you’d likely agree running a vent across the room to an external wall would be ugly and I don’t want to drill a big hole through the original brick work. Even once outside, the building is wrapped by a large double storey veranda with original iron work and the piping could get messy getting right to the outside. Moving heater location is also not an option due to room layout plus part of it is bringing a fire back to the focal point of the room.

 

[johneh]

I wish I had the installation manual but I don’t.

Without the manual or the name of the stove everything we say
is speculation because every stove manufacturer is different

 

[Jeff S.]

I have 3" insulated stove pipe from stove to ceiling going into a 3" - 4" adapter that was is attached to my existing 6" insulated woodstove flue pipe going thru attic and roof. It is about an 8' run of 4" flexible pellet flue inside the 6" insulated flue sealed on top. I have had no issues with draft or otherwise. I do clean it 2x during winter just bc I want to make sure ash doesn't build up at bottom of flue behind the stove.

 

[creztor]

Another person from Australia Hi! Anyway, run standard pipe size. My install is maybe 7m but obviously not as long as yours. I know someone with maybe 8 to 9 but still a bit shorter. Anyway, what model pellet heater are you installing? Is it a Ziegler brown from BBQs galore or something else? I ask because as above you need to know how to adjust exhaust fan voltage to overcome any issues due to length of flue. I'm in Tas and luckily down here pellet heaters are at least not completely unknown but most people still have never heard of them.