Aspen C3 Baffle Replacement

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fbill b

New Member
Oct 16, 2021
2
New Hampshire
Hi, Everybody,
My girlfriend bought the new Aspen C3 last summer,. By December she had broken the baffle and chopped up the refractory blanket. I immediately searched for replacements, but everything was sold out. I figured this must be a common problem. I spoke with her chimney sweep who told me what a big project replacement is.
He advised me not to attempt to install the new refractory blanket.
I decided to not attempt the blanket unless we had some untoward results. The stove had worked fine the previous season without most of it.
On each side holding in the firebricks are what the parts schematic calls side covers. These are stainless steel and each is held in with 12 mm bolts. The baffle sits on top of these. The blanket sits above this. I removed the two front bolts on each side and loosened the back bolts on each side. The covers pivoted downward far enough to insert the baffle through the door. As the baffle reached the end of its inward travel, it was necessary the rotate the assembly upward to allow the baffle to clear the top.
It was a fifteen minute job.
 

wjohn

Member
Jul 27, 2021
211
KS
Thank you so much for sharing this. I was wondering if I could drop the baffle for cleaning, and if that would be harder or easier than raising the telescoping pipe section above the stove. I am hoping I can drop the baffle the way you did and slide a bag or something on top of the blanket, under the firebox flue outlet to catch crap during cleaning. That way I wouldn't have to touch the blanket.

I smacked my baffle pretty good with the poker in my first fire or two but didn't puncture it. I have been much more careful since. I was spoiled with the steel baffles on the stoves I grew up with - but they didn't burn as clean and efficiently as the newer stoves do, either.
 

fbill b

New Member
Oct 16, 2021
2
New Hampshire
I can not say anything about the blanket. I arrived at her house after the chimney cleaner had vacuumed out the remnants of her mangled one, therefore I could not see how it sat above the baffle. Her stove is installed in a huge fireplace (5'x3' opening) with stainless liner going straight up the chimney through the damper opening. She should have been given a massive discount for the easy job he was given: with the baffle out of the way, his brushes went right up.
I did monkey with the new blanket. It is obvious where it sits, and it appeared there are small nooks and crannies into which it must be fitted. This job might be better performed by removing the top, but, then again, this is all about saving time and labor. Maybe someone will chime in with just what the refractory blanket does.
 

Abrahampost

New Member
Sep 8, 2021
5
Vermont
I've had to do the baffle/temp probe after it was broken during a cleaning and decided to do the blanket as well. It is pretty easy to seat in with the baffle out then just bolt the baffle back in.

I'd say total time including pulling the stove out of my fireplace was two hours. The purpose of the blanket is to allow the baffle to get extremely hot for secondary burn while not overheating the temp probe above it that controls the air intake of the stove.
 
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wjohn

Member
Jul 27, 2021
211
KS
I've had to do the baffle/temp probe after it was broken during a cleaning and decided to do the blanket as well. It is pretty easy to seat in with the baffle out then just bolt the baffle back in.
That's a good point I hadn't thought of. I was planning on pulling the baffle and blanket from the inside of the stove, without having to disconnect my stove pipe. The probe will still be there so you have to be extremely careful to not ram the brush down into it with these stoves.
 

Abrahampost

New Member
Sep 8, 2021
5
Vermont
That's a good point I hadn't thought of. I was planning on pulling the baffle and blanket from the inside of the stove, without having to disconnect my stove pipe. The probe will still be there so you have to be extremely careful to not ram the brush down into it with these stoves.
Yeah with supply chain delays and such I've gone to keeping a backup baffle, probe, and blanket in the basement. I think total cost is around 150 bucks if you hunt around different part suppliers.

I do love the stove and it's ease of use so anyone can maintain the fire through the day. Only downside are some delicate/wear parts that can be broken during cleaning.

I built a rolling cart with a trolley jack to pull the stove out for cleaning. Takes 10 minutes to unhook the pipe and slide the stove onto the hearth, I clean the stove myself and then the chimney people can really go to town without worry.
 

tyrr

New Member
Jan 20, 2022
5
north mi
Hello,
I hope you or someone else can give me advice on how to handle an issue with the superwool blanket in my fairly new Aspen C3.
Here's the situation: A brand new Aspen C3 was installed in my house in October, 2020. It is a hearth mount (sitting in fireplace).
It vents through a stainless steel liner (6" diameter, not insulated) that runs up through an original masonry chimney on an outside wall.
There is a cap on the liner. The chimney was built to code near a roof ridge (Outlet is about 4' above ridgeline). From the flue collar on the stove, the liner extends 15'. The liner has no sharp bends; it snakes through the fireplace flue in a very gentle S-curve.

We have fired the stove since its installation about 15 times. It is not used for whole house heating; only to heat a living room- dining area
on the coldest days. Firewood to date has been exclusively dry beech. In fact, I use only cutoffs of 3/4" x 4" x 12-18" from wood floors I have installed. There is a lot of it. When starting a fire, feeding the stove, raking embers, etc. I have adhered only to the operator's manual that came with the stove. Every time, in my not real-experienced opinion, the stove has done beautifully. The starting (kindling)
fires have burned hot. New wood placed on embers ignites and burns evenly. Loading the stove about half-full has given burn times of five to 6 hours. The air shutter in the back seems to work properly. Same with the thermostatic control. I have never had to crack open the door of the stove to draw more air in. No smoke has ever come out of the air inlet. Everything seemed perfect . . .

Until two weeks ago. It was a cold Sunday morning; 3 degrees F at 10:00 AM and windy with gusts approaching 30 MPH. I started a kindling fire; went well. Added a handful of beech; great. After an hour I put two pieces of beech in the stove. I went downstairs to do something, and after 10 minutes my wife called me up and said that she heard a loud sound in the stove that sounded like "a spring breaking." I looked through the stove's glass door and saw a solid roiling wall of smoke. Not knowing what else to do, I just watched and waited. I went out to check the chimney, saw smoking coming out but only a little. Well, it took 7 hours for the smoke to finally "clear"
out of the stove. The stove was very warm the entire time. I opened the stove's door early the next day, and (you probably knew) all the cast iron inside and the glass in the door had a 1/32" of glassy creosote coating them. I checked the air shutter in the back; it was fully open. With a flashlight, I peeked up above the refractory baffle (not much space) and saw what looked like the superwool blanket pulled up into the flue collar. I tried to pry the blanket back down with a thin steel rod but no dice. So I removed the side covers and the baffle (gently) and had to give a good tug on the blanket to pull it out of the flue collar. The blanket was permanently deformed in the shape of a dome with a 1" apex.

Anyone seen or heard of this? The blanket looks like it was "sucked" right up into the collar. Negative static pressure at the chimney top?
A freak wind?

I'm glad you explained the purpose of the insulation blanket. It is has to be in there. I will put a new blanket in the stove. There are 1" x 1" channels in the stove's sides that the blanket should be fitted into. But I'm worried about a repeat. To keep the blanket in place, I'm thinking of fitting a bar of 1/8" x 1" stainless steel tight in the channel sides and above the insulation blanket. Centered below the flue collar. Good idea? Someone have a better solution? I contacted Vermont Castings; just got a standard response . . . "don't alter the stove."
In anticipation for some help, thank you very much!
 

Abrahampost

New Member
Sep 8, 2021
5
Vermont
That is quite an issue, glad everyone was safe through it. I have never had such an issue, but have had the thermostatic control go on my Aspen after two years. It caused the stove to smoke into the house badly as the draw had no inlet to pull from. When I replaced it, the super wool was absolutely wrecked as well. My guess is whoever cleaned it last didn't actually pull the plate and clogged it up.

I'd think it was a freak occurrence along with a part failure.
 

wjohn

Member
Jul 27, 2021
211
KS
That's quite an experience. I have not had my stove apart to see how the insulation blanket is captured, or if it just kind of hangs out up there with a little compression on it between the stovetop and things under it. Mine's burned in 30 MPH sustained and 50 MPH gusts without this happening. I would venture to say that my insulation blanket has not budged from when I installed the stove last fall.

As I recall the temp probe is on top of the blanket? So it would've had to rip or pull around that to get sucked up into the flue outlet, unless the blanket was incorrectly installed over the probe by the factory?
 

tyrr

New Member
Jan 20, 2022
5
north mi
Thank you Abrahampost and wjohn for responding. Abrahampost, I'm sure glad my thermostatic control didn't break like yours did (the probe looks fine; I will try to test it before installing a new Superwool blanket). If the air shutter had been closed when the stove filled with smoke, the smoke may have leaked slowly into the house. And my wife with a living room full of nice, new furniture. I would be living in the dog's house; or the ice shanty or the sugarbush shack!

wjohn, the tempprobe looks fine. In the manual's parts schematic you'll notice a notch in the back of the Superwool blanket.
The notch is 1" x 3". I think this saved me by clearing the probe when the blanket was sucked up into the flue collar. Whew!
 

wjohn

Member
Jul 27, 2021
211
KS
From what I remember before I hooked up my stove pipe, the probe extended a good 2" or so over the insulation blanket, past that notch. I think that notch is just for fitting around the cover for the bimetallic spring and chain bracket. Sounds like it still pulled the blanket past the probe in your case.

It's still odd. That blanket never should've moved.
 

tyrr

New Member
Jan 20, 2022
5
north mi
See what you mean! I think I wasn't explicit about the position of the super wool blanket. When I removed the baffle the blanket was still generally fitted into the 1" x 2" deep channels that are integral to the stove's cast iron sides. The blanket had been pulled into the flue collar and had the shape of a dome 6" in diameter when I pulled it out. The blanket had deformed so obviously some material probably was pulled from the side's channels. What caused it? You're right; odd as heck! Maybe something will strike you later . . . thanks.

I don't know how, but the probe looks fine; parallel to the stove's lid.

I have a friend who's an aeronautical; will talk to her about it.
 

wjohn

Member
Jul 27, 2021
211
KS
For a visual for anyone reading through this thread, here is a picture of the probe location, as seen through the flue exit. The insulation blanket is below it. You can see how the temp probe could get damaged during cleaning (especially if the baffle and blanket are removed from below and the pipe is not disconnected from the stove) if you don't know to watch out for it.

20220130_122134.jpg
 

bikeshopguy345

New Member
Feb 6, 2022
27
North MS
We are on our first season with the Aspen C3 and very pleased so far. To piggyback on the thread I have 2 questions:

1. When it comes time for spring cleaning would you recommend getting on the roof and brushing down, or pulling the baffle and going up? I'm comfortable doing either(I installed the whole system). I really want to avoid disconnecting the telescoping chimney connecter. I know it'll scratch it and need to be repainted if I do. I also don't want to damage the probe or superwool ceramic blanket.
2. What do you think about installing a stainless steel plate underneath the baffle to protect it? I have noticed some pretty significant gouges to the baffle board already from me playing "Firewood Tetris."

Thanks everyone. This forum is such a great resource.
 
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wjohn

Member
Jul 27, 2021
211
KS
We are on our first season with the Aspen C3 and very pleased so far. To piggyback on the thread I have 2 questions:

1. When it comes time for spring cleaning would you recommend getting on the roof and brushing down, or pulling the baffle and going up? I'm comfortable doing either(I installed the whole system). I really want to avoid disconnecting the telescoping chimney connecter. I know it'll scratch it and need to be repainted if I do. I also don't want to damage the probe or superwool ceramic blanket.
2. What do you think about installing a stainless steel plate underneath the baffle to protect it? I have noticed some pretty significant gouges to the baffle board already from me playing "Firewood Tetris."

Thanks everyone. This forum is such a great resource.

Welcome to the forum!

1. You would have to remove the insulation blanket in addition to the baffle in order to clean from below, or allow the cleanings to drop down into the firebox even if cleaning from above without undoing the pipe. At first I did not want to mess with my telescoping stovepipe piece either, but in my opinion that is by far the best way with least risk of damage to the baffle, insulation blanket, and probe. The insulation blanket is pretty delicate and I have avoided removing it. Plus, you can get a good look at the probe as well. No matter which method you choose you will have to watch out for the probe. Personally I much prefer to get up on the roof and clean top down, with a bag over the stovepipe disconnected at the stove outlet. I do not have all winter snow/ice on the roof in my climate though. Seems like you shouldn't either :)

2. You do have to be careful with the baffle, just like you do with any stove that has a non-metallic baffle. I do not know what other effects adding a stainless plate underneath the baffle would have besides pushing the current baffle up higher. I'm sure other folks have had that thought before with other stoves that use non-metallic baffles so you might search around, not specific to the Aspen C3. Personally I run mine fairly hard and don't think the risk of changing something critical there is worth the possible gain of me being able to just ram splits into the firebox. I don't have too much trouble being careful with it now that I'm used to it.
 

bikeshopguy345

New Member
Feb 6, 2022
27
North MS
Welcome to the forum!

1. You would have to remove the insulation blanket in addition to the baffle in order to clean from below, or allow the cleanings to drop down into the firebox even if cleaning from above without undoing the pipe. At first I did not want to mess with my telescoping stovepipe piece either, but in my opinion that is by far the best way with least risk of damage to the baffle, insulation blanket, and probe. The insulation blanket is pretty delicate and I have avoided removing it. Plus, you can get a good look at the probe as well. No matter which method you choose you will have to watch out for the probe. Personally I much prefer to get up on the roof and clean top down, with a bag over the stovepipe disconnected at the stove outlet. I do not have all winter snow/ice on the roof in my climate though. Seems like you shouldn't either :)

2. You do have to be careful with the baffle, just like you do with any stove that has a non-metallic baffle. I do not know what other effects adding a stainless plate underneath the baffle would have besides pushing the current baffle up higher. I'm sure other folks have had that thought before with other stoves that use non-metallic baffles so you might search around, not specific to the Aspen C3. Personally I run mine fairly hard and don't think the risk of changing something critical there is worth the possible gain of me being able to just ram splits into the firebox. I don't have too much trouble being careful with it now that I'm used to it.
Thanks for the reply! I will report back when I do spring cleaning to let everyone know how it goes. Snow certainly won't be a problem here.

I inspected the baffle a bit better tonight before I lit the stove. One of the gouges is maybe 1/2 way through:oops:...whoops. I will definitely be more careful. I really didn't appreciate how fragile it is. An Aspen C3 is definitely not the fireplace at deer camp.
 
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wjohn

Member
Jul 27, 2021
211
KS
Thanks for the reply! I will report back when I do spring cleaning to let everyone know how it goes. Snow certainly won't be a problem here.

I inspected the baffle a bit better tonight before I lit the stove. One of the gouges is maybe 1/2 way through:oops:...whoops. I will definitely be more careful. I really didn't appreciate how fragile it is. An Aspen C3 is definitely not the fireplace at deer camp.
I smacked mine with the poker maybe my 3rd or 4th fire. Didn't quite dent it halfway through and I've been much more careful since then. Honestly I rarely even use the poker now since the stove burns so well and doesn't need much help. We just have to be easy when playing Tetris on loading.
 

tyrr

New Member
Jan 20, 2022
5
north mi
1.) Agreed, that superwool blanket is delicate. (See my experience earlier in this thread. I still don't have a good answer for why that blanket was "sucked up" into the flue collar.) I would prefer not to detach the liner connector; like wjohn's earlier idea of sliding a plastic bag up on top of the blanket-baffle to catch debris; wonder if he's worked on that angle. And I seem to recall that someone marked the
chain on their chimney brush to stay a couple inches above the temp probe.

2.) Would look at the heat transfer characteristics of refractory cement vs. stainless steel, but why not just replace the refractory baffle with a stainless steel plate cut to fit the side cover channels that hold the current baffle?
 

wjohn

Member
Jul 27, 2021
211
KS
I wasn't suggesting sliding a bag on top of the baffle - just pulling the telescoping pipe up and putting a bag under it. It would be difficult to get a bag or sheet of plastic back up above the baffle and insulation blanket from inside the stove to begin with. There is little room to work with there. Plus, you wouldn't be able to clean up any existing accumulation around the probe if you don't take something apart - either the baffle/blanket from below, or the pipe from above. However I was the guy that wrapped a piece of duct tape around my chimney brush rod at the correct spot to not go down any farther and damage the probe/blanket.

If you completely replace the baffle with a stainless plate, I suspect you would lose efficiency (and probably increase emissions as well). Just a steel plate would radiate more heat upwards and out the flue. The baffle (made out of whatever non-conductive material) keeps heat down below in the firebox. Practically, I have no idea what percentage loss of efficiency you'd be looking at. There may be other concerns with doing this as well in a stove not designed for it.
 

bikeshopguy345

New Member
Feb 6, 2022
27
North MS
I wasn't suggesting sliding a bag on top of the baffle - just pulling the telescoping pipe up and putting a bag under it. It would be difficult to get a bag or sheet of plastic back up above the baffle and insulation blanket from inside the stove to begin with. There is little room to work with there. Plus, you wouldn't be able to clean up any existing accumulation around the probe if you don't take something apart - either the baffle/blanket from below, or the pipe from above. However I was the guy that wrapped a piece of duct tape around my chimney brush rod at the correct spot to not go down any farther and damage the probe/blanket.

If you completely replace the baffle with a stainless plate, I suspect you would lose efficiency (and probably increase emissions as well). Just a steel plate would radiate more heat upwards and out the flue. The baffle (made out of whatever non-conductive material) keeps heat down below in the firebox. Practically, I have no idea what percentage loss of efficiency you'd be looking at. There may be other concerns with doing this as well in a stove not designed for it.
I agree on the two points:
1. To properly clean this stove I think I am going to have to disconnect the telescoping pipe. I can just repaint it if I need to.
2. I don't think completely replacing the baffle board with stainless steel would be a good idea. I don't really know for sure, but I think it could possibly transfer more heat, however, I do plan on evaluating the possibility of retaining the baffle board and giving it a thin sheet of stainless steel armor when I do a spring clean. I'm not super set on this, it may prove impractical. It also might make more sense from a cost standpoint just to buy another baffle and keep it as a backup. I'm not sure what the baffle price vs stainless steel sheet price is.

I will report back on this after spring cleaning.
 

bikeshopguy345

New Member
Feb 6, 2022
27
North MS
I did some cleaning yesterday. Disconnecting the telescoping connector pipe is very easy and it doesn't really even scratch the paint. Getting on the roof for top down is what is best for me with a garbage bag cinched around the pipe inside to catch the debris.

Regarding my damaged baffle board: I removed the "side covers"(stainless steel brackets) that hold the baffle in place. While a 12mm wrench may work, 7/16 was the more appropriately sized wrench. I tried to remove the two front bolts from each side, and loosen the back. The assembly was able to rotate down, but I still couldn't get the board out. I was trying to be super careful with the super wool above. I ended up removing all of the bolts and removing both brackets completely.

It was very windy and with the baffle removed I did notice the super wool blanket wanted to suck upwards into the flu with big gusts. I would assume this shouldn't be a problem with the baffle in place though(it seemed to only occur without it) because it blocks a direct path for the air to be lifting the underside of the super wool.

I decided against the stainless steel sheet metal idea. I have no idea what kind of stainless steel I would need or how thick it would need to be. I also don't have any locally available. My stove is running perfectly now and I didn't want to change any variables.

I had several gouges in the baffle, but it was still structurally sound, so I just flipped it upside down and put it back in. Now the "good" side is what you see in the firebox. I noticed the baffle had developed a very slight bow because there is now a 1mm gap above the secondary air intake in the top back of the stove, but don't think this will be a problem.

Replacing the brackets was a bit fiddly. Getting the bolts in wasn't the biggest problem. There is tiny rope gasket behind the brackets in channels in the body of the stove. I assume they are for expansion and contraction purposes, because the gasket doesn't go all the way around the channel that the brackets bolt to. There is a 3-4inch area at the top with no gasket. On one side I had to use some small pieces of masking tape to keep the rope from falling out. I'm pretty sure it'll just burn up and be gone.

I think I should get another few seasons out of the baffle by actually being careful and not trying to wedge that one last piece of wood in every time. If I do break it, I plan on replacing it with an OEM baffle. I might buy one to keep on hand as a spare.
 
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tyrr

New Member
Jan 20, 2022
5
north mi
Referring to my very first posting, my stove was fully assembled (the baffle was in place) when our mishap occurred. The superwool blanket was pulled up into the flue collar and deformed. It took a little bit of force to dislodge it after I removed the baffle. The baffle was a little bowed, so I decided to buy a new one; still waiting on the new one which I gave a deposit for. And when I put it all back together I'll have to replace some of the rope gasket that you mention, as well the deformed superwool blanket. I can only conjecture that the superwool blanket was sucked up into the flue collar during an extreme wind gust, and am I correct in thinking that this implies a vacuum? I am working on an idea to fix the superwool blanket with a piece of stainless steel bar. I have seen on threads relating to other make stoves that weights are sometimes used to hold the insulation blankets in place; for what reason (perhaps the same as mine?) is not explained. Do you think it's a good idea to try and fix the superwool blanket in its intended position?
 

bikeshopguy345

New Member
Feb 6, 2022
27
North MS
I believe you are probably correct about wind gusts being to blame after what I witnessed while cleaning mine.

If you live in an area with frequent high winds you might want to research chimney cap type. I’m not sure that will be your best solution though. I’ve personally found some of that information a bit confusing.

I don’t think trying to secure the super wool is a bad idea. My only concern would be compressing it too much. I believe it would lose some of its insulating ability if compressed.

Please keep us posted with what you come up with.
 
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EbS-P

Minister of Fire
Jan 19, 2019
2,429
SE North Carolina
I believe you are probably correct about wind gusts being to blame after what I witnessed while cleaning mine.

If you live in an area with frequent high winds you might want to research chimney cap type. I’m not sure that will be your best solution though. I’ve personally found some of that information a bit confusing.

I don’t think trying to secure the super wool is a bad idea. My only concern would be compressing it too much. I believe it would lose some of its insulating ability if compressed.

Please keep us posted with what you come up with.
Some stoves use a piece of iron to weigh down the insulation. Loosing a bit of R value is better to me than getting the flue obstructed.
 

bikeshopguy345

New Member
Feb 6, 2022
27
North MS
Some stoves use a piece of iron to weigh down the insulation. Loosing a bit of R value is better to me than getting the flue obstructed.
Agreed. I suppose the whole thing wouldn’t need weight, maybe just a part of it?

Interested to see what @tyrr comes up with.

Fortunately mine has stayed put without intervention.