2021 Vermont Castings Aspen C3 Install

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wjohn

Burning Hunk
Jul 27, 2021
237
KS
Finally got my Aspen C3 install all done. I ripped out the FMI 3600 prefab fireplace that was there (maybe I can get a few bucks for it on CL/FB marketplace before I junk it? ha), the existing framing/structure for it, and the 8" air cooled chimney. Installed new Metalfab 6" chimney, repaired the roof, all the drywall, painted, and put down some new tile. Originally I was going to just use the existing tile throughout but it has been discontinued, so I picked out the charcoal-ish tile for a defined hearth area.

The stove is much smaller than what I grew up with - see soup can pics for scale. Those tiles are 12 x 12 for perspective. My house is reasonably well sealed and is under 1000 square feet. I have some well-seasoned wood but most of it is cut into 8-10" lengths that I used in the old fireplace. VC recommends 16" with 18" length being the max. I measured and you have 18.5" front to back, below the front air outlet structure behind the door.

The OAK inlet is a little higher than I'd like but VC gives no guidance or restrictions on this in the installation manual. Mine is located up on the wall where it is due to being leftover from the fireplace.

My hope is to keep this updated throughout the winter, especially since these stoves are pretty new and from what I gathered had a few manufacturing issues early on. This one has an end of July 2021 manufacturing date. I need to do a few break-in fires first, of course, but we're in the low 80s here today.

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That's a nice improvement. It finished out well.
The OAK inlet is a little higher than I'd like but VC gives no guidance or restrictions on this in the installation manual. Mine is located up on the wall where it is due to being leftover from the fireplace.
The OAK is supposed to be lower than the firebox. This is to avoid the OAK acting as a chimney in the event of draft reversal. The illustrations in the install manual show this, but it would have been better if they also explicitly stated this.
 
That's a nice improvement. It finished out well.

The OAK is supposed to be lower than the firebox. This is to avoid the OAK acting as a chimney in the event of draft reversal. The illustrations in the install manual show this, but it would have been better if they also explicitly stated this.
Thanks. The only relevant information I have been able to find on some outside air kit installation sheets is that it must terminate no higher than 3' below the chimney termination, which I am well below here (by about 13'). I found that soffit installations were allowed by the OAK manufacturers if the 3' rule was met. Does NFPA or some other code I don't have access to state otherwise?
 
It only got up to the low 60s today and it was a bit chilly with the sun down... Time for the first break-in fire! I will have to learn how long to leave the door cracked on startup. Some of these smaller pieces of honey locust were a little pithy around the edges so that didn't help. I did get it to a point where I could shut the door and I am very excited about how much heat it was putting out for only having some small kindling and 3 ~3" diameter x 6" long locust branch pieces in it. This got the stovetop temp up to 250 or so - enough that I needed to open windows for fresh air with the paint heating up for the first time. I think the cooktop area is going to be pretty handy. From the parts diagram it looks like they carved out the insulation in that area so that it gets enough heat directly to the cast stove top.

I did note I had some smoke spillage early on, when I was trying to close the door too soon and then reopened it to allow more air in. I think the height of the door relative to the baffle probably contributes to this, but mostly operator error. The stoves I grew up with had more distance between the top of the door and the baffle, so may have been more forgiving.

Enjoy some poor quality pictures from my low-end smart phone.

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Thanks. The only relevant information I have been able to find on some outside air kit installation sheets is that it must terminate no higher than 3' below the chimney termination, which I am well below here (by about 13'). I found that soffit installations were allowed by the OAK manufacturers if the 3' rule was met. Does NFPA or some other code I don't have access to state otherwise?
Where did you get that 3' thing? I have never seen that anywhere
 
That is in the section referring to gas appliances. Woodstoves the oak needs to be below the firebox level unless otherwise specified by the manufacturer. VC doesn't specify this. But their instructions are very poor in that section.
That's in the section that applies to both wood and gas, then the specific wood or gas instructions are after that generic section. Granted, it's likely not applicable to my stove, but VC doesn't give any further OAK inlet height requirements in the Aspen C3 manual.

You guys seem to be thinking I will run into issues here, is what I'm gathering? For sure, I would not have located the OAK inlet 2' up on the wall if I were starting from scratch, but I didn't find any documentation or references to standards indicating that the height of my existing one would be an issue.
 
That's in the section that applies to both wood and gas, then the specific wood or gas instructions are after that generic section. Granted, it's likely not applicable to my stove, but VC doesn't give any further OAK inlet height requirements in the Aspen C3 manual.

You guys seem to be thinking I will run into issues here, is what I'm gathering? For sure, I would not have located the OAK inlet 2' up on the wall if I were starting from scratch, but I didn't find any documentation or references to standards indicating that the height of my existing one would be an issue.
I will find the code reference tomorrow. I know it's there though.

You are correct I looked again that is in the general instructions. But that kit says it's for fireplaces not woodstoves. There is a big difference
 
Would it be all right to go down with the OAK pipe when it comes out of the wall so the pipe makes a U-shape? Would that help keep the flow from reversing?
I would use black piping so it doesn't stand out so much.
 
Yes and the other illustration shows straight out and through the wall. It would be good for VC to add explicit language about the OAK height to the instructions.
 
Would it be all right to go down with the OAK pipe when it comes out of the wall so the pipe makes a U-shape? Would that help keep the flow from reversing?
I would use black piping so it doesn't stand out so much.
I would like to do something to dress that up a bit, but I wasn't able to find anything made from darker colored metal in stock locally at the stores I checked. Those bits are easy to access so I can always replace them later.

But, am I hearing from everyone that I need to quit using the OAK setup I have due to the inlet height? I can always just not use the OAK for this winter and screw around with putting in a new OAK inlet hood in a lower spot on the wall at a later date, if that is going to be necessary.
 
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But, am I hearing from everyone that I need to quit using the OAK setup I have due to the inlet height? I can always just not use the OAK for this winter and screw around with putting in a new OAK inlet hood in a lower spot on the wall at a later date, if that is going to be necessary.
That's a safer plan.
 
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That's a safer plan.
Phooey. Well, that's easy enough for now. Just would be nice to see some requirements added to the owner's manual if this is the case. Of course, I am too cheap for NFPA membership, if it is hiding in their standard somewhere, so that may be on me. I have found the 2003 and 2006 revisions floating around the internet and they do not yet say anything about location of the inlet in those.
 
Agreed. As a stove owner, it would be good for you to pass this on to Vermont Castings for the next manual revision.
 
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I had the second break-in fire last night. I had some trouble with smoke spillage early on which I think was due to it being in the low 70s outside and upper 60s inside, but I'm glad I did that so I could open the windows and wasn't high on paint fumes for the rest of the night. I would never normally have a fire in anything over 60 degrees, for sure.

Tonight it's more like 50 outside and 69 inside at 6pm when I started the fire - no issues with draft. Keeping it small-ish for the 3rd fire, I loaded four ~4" diameter x 8" long locust splits in and after leaving the door cracked for a bit was able to set it and forget it. By 9pm the temp was up to 75 inside and still 50 outside, with a 25 MPH wind (gusts up to 50 MPH... not uncommon here). It's far from cold yet but I am confident this stove will put out enough heat for my small house. I am amazed how long it lasts when it looks like it's getting down to coals. I don't know if I'll quite get the advertised 10 hour burn time but I bet I can get close when I fully load it up - and it darn well better, as I'm hoping that's the tradeoff for losing manual air control.

Flue temps have been pretty low but I expect that with these smaller shorter fires here at first.

My main gripe so far has been that the glass totally blacks over at some point towards the end of the burn cycle. Like, can barely see a hint of an orange glow through it. Maybe it gets a little smoky at the very end of the coals burning down? That stuff is hard to get off and blocks the glass solid. I'm going to have to buy some proper stove glass cleaner and give that a try. The only place that stays clean is the 3/4" or so right above the air wash vents at the bottom of the glass.

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The draft will get notably better at 40º or below. Hopefully, that will translate to a hotter fire and cleaner glass. Locust should provide good long burns. Do you have 16" splits too?
 
The draft will get notably better at 40º or below. Hopefully, that will translate to a hotter fire and cleaner glass. Locust should provide good long burns. Do you have 16" splits too?
I do not. I had sized most of this stuff to Jenga-style fit into the old prefab fireplace which was very shallow and sometimes difficult to keep burning. At least it is easy to fit into this stove, even if it's not totally optimizing the firebox.

From here on out I can cut to 16". I have some smaller standing dead locusts that I can cut and split now, and they would probably be okay to burn later in the winter, if my current seasoned stockpile runs out.
 
Have you dipped a wet paper towel in ash and wiped the dirty glass? Have a dry towel to quickly follow up. Done. Usually this method works pretty good.
 
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Have you dipped a wet paper towel in ash and wiped the dirty glass? Have a dry towel to quickly follow up. Done. Usually this method works pretty good.
I have not. VC warns about ash possibly etching the glass in the manual, so I was figuring I should avoid that even though I have seen it mentioned as a good cleaner by many folks.

Edit: Re-read and they warn about ash residue etching it if left on, not specifically rubbing ash as a cleaner.
 
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Did not have much luck with the commercial stove glass cleaner or with ash. Both removed some of the lighter stuff but I have a good layer of really thick, absolutely baked on stuff that will come off if you physically scrape it with something like an old putty knife. It laughs at the other cleaners. I didn't want to scrape too much and risk getting the glass, so I stopped and figured I'd see if a good hot fire would help at all. I wonder if any of it is stuff that baked off the inside of the stove from the break in fires? Maybe it's just caked on carbon.

40 degrees outside and 58 inside when I got home tonight. I picked up a cheap HF IR thermometer on the way home to try out. I have the back of the stove about 1/3 full of locust and mulberry and it has been humming along nicely. The automatic air control seems to be doing its thing. The center of the cook plate peaked at about 650 degrees an hour and a half later, and 2 hours later the house is 65 degrees. External flue temps were about 250 2' above the stove, and 175 near the ceiling. So far I'm happy. I did finally notice smoke/haze in the house, probably from the single wall pipe finally being hot enough to bake the paint a little, so I've cracked the windows open at this point.

I did smack the baffle pretty good with the poker earlier while flipping a log up. I have been spoiled with stoves with steel baffles in my past. No hole, but I'm going to have to be more careful.
 
If you can get it off, maybe try to do a high burn more frequently so that it does not build up so much?
 
If you can get it off, maybe try to do a high burn more frequently so that it does not build up so much?
I am optimistic it won't be an issue going forward. I would normally never make the short-burning small fires that I did for break-in. So far so good in the cleaned areas with tonight's more normal fire but we'll see what it looks like in the morning.