Hearthstone Shelburne 8372 Operation

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Feeling the Heat
Oct 11, 2020
303
new hampshire
I haven't found any reviews or feedback on this stove and I've had a couple of people reach out with questions about my experience with it, so I figured I'd do my part and contribute what I've learned so far.

Stove: 2021 Hearthstone Shelburne (8372)
Flue Exit: Rear
Chimney: Exterior masonry chimney with 8"x12" terracotta tile flue, 17.5 ft SS liner (non-insulated) inside tiles with top plate/cap, liner connected to a capped tee, 22" snout into adjustable 90 degree elbow (single wall)
House: built 1987, ~2000 sq ft, 2 story, newer windows, relatively open concept on main floor (where stove is located)
Temperature Probe: IR Gun

First year with the stove and chimney setup so I don't have a lot of experience, but overall I'm happy with the purchase. My complaints are probably less about the stove and more on the differences in operation between a cat-hybrid and the old VC vigilant I had prior to the Shelburne. I will say that I wish the firebox was deeper to support N/S loading, or that there was a side-load door.

Cold-Starts:
You need to have sleepers on the bottom of the firebox to elevate the splits to increase air-flow since the primary air is front bottom center of the box. This requires cutting splits to size or in half to fit N/S in the box. If there are ashes make sure to dig a trough front to back in the center to allow air flor from the primary inlet. Top down is the method to use. I always pre-heat the flue with a heat-gun. Primary 100 % open, door cracked, light ends of knotted up newspaper. Once the larger kindling has caught fire I'll slowly close the door and latch it (1-3 minutes depending on outside temps).

I have had issues with smoke-rollout when opening the door; the remedy has just been to not open the door unless I'm reloading at least smoke isn't spilling into the room in this scenario. General consensus is that an OAK/more chimney height would be beneficial, but the stove seems to be drafting well during operation and with my current lack of experience I'm actually having a hard time maintaining lower STT as it is.

Hot Reloads: The handful of times I've done this (mild winter so far) I've waited until the STT was about 300 F. Made a channel in the coals down the center of the box for the primary and then loaded. Once I see flames on the bottom splits I latch the door.

Cat Activation: Following the manual instructions has you running 100% open primary for 20 minutes after cat activation at least on cold starts. I've tried this twice and both times I had trouble controlling the burn after engaging the cat. The cat probe rose to the upper limit of the active range.

Per general guidance on this sub the sooner you start shutting things down the better. I've been activating the cat right after the probe is in the active range and have had better success on controlling the cat temperature.

Controlling the Burn-Rate: As I said I attribute most of my troubles with controlling the burn to lack of experience with cat-hybrid stoves. However, 75% of the primary air control range seems to be useless. A perfect example of this would be last night I reloaded with 5 splits (1 large, 4 medium - so not even half of a full load). Outside temp was 25 F, STT was 300 F when I reloaded and the cat probe was still in the active range. Once the flames were well established (maybe 3 minutes) I engaged the cat and started to reduce the air. 50%, 5 min, 25%. At this point secondaries were going well and 5 minutes later I closed it down to ~12.5%. I left it on this setting for the rest of the burn. STT reached 650 F, and 12" up the flue was around 375 F (that's all of the flue I have access to). 650F STT was very localized right above where the by-pass door is in maybe a 1"x1" area. 2" away from that area the temp dropped significantly ~100F. On top of the top exit cap (directly above the cats) it was roughly 475 F. Again all taken with an IR gun (rutland magnetic temp gauge was close but reading lower. I attribute that to the artistic texture the stop has on the ST). I can't imagine what the temperature would have been if the primary was at 25%+ open.

I'm not sure if I should be looking for the single hottest spot on the ST to test. I'd love to be able to maintain a lower STT. 1 to extend the burn time, but 2 because the house doesn't need all the extra BTU output to stay in the lower 70s.

Outstanding questions:
  1. Is it normal for most of the burn rate control to be in the last ~12.5% of the primary control?
  2. Are there tell-tale signs of the fire moving to the coal stage? I've had some fires I thought were transitioning to this stage, but instead the stove back-puffed from what I assume was closing the primary down too much too quickly
  3. Is it possible to have mellow secondary combustion and maintain lower STT? or does secondary combustion only occur above X STT?
 
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Yes, excellent and helpful report. We are all learning the behavior of the new hybrids so I won't interject any comments other than it sounds like your firewood is nicely seasoned.
 
Yes, excellent and helpful report. We are all learning the behavior of the new hybrids so I won't interject any comments other than it sounds like your firewood is nicely seasoned.
It's been stacked/covered for 14 months at this point. Not sure how long it was cut prior to it being delivered to me. I believe its a mix of oak/maple/white ash (mostly ash as those trees are dying around here). read between 12-15% last time I checked a split

I'm wondering where I should be testing the stove top temperature. For the old Vigilant they said to do it in the corner of the griddle; I'm assuming this was because the gases were concentrated in the center of the griddle before they headed out the flue. Based on the firebox/baffle design of the Shelburne I'm wondering if I should be taking the temperature at a different location.
 
Finally have some cool weather here after a real mild stretch. Roughly 25 F today, no wind, cloudy skies. Did a cold start, Lincoln log style top down. 2 large. 2 small, kindling. lwas able to control that to keep it below 600 F.

4 hrs later had a smaller bed of coals. Pulled them to side/front to let the primary air have a channel. Put on 4 splits roughly 18"x5"x3" in size on average. Mix of ash, maple, something else i couldn't identify. Door cracked splits caught in 10 minutes (waited too long to reload). Closed the door with primary 100%open. 5 minutes later cat was in operating range, closed bypass.

Over the course of 45 minutes closed the air down to 90% closed (hard to tell, need to add markings) and had a nice STT of 550 confirmed with IR gun and cat in middle of active. Secondaries going and flames just lapping the top of the wood. Images below.


20220103_150730.jpg

20220103_150817.jpg


20220103_150827.jpg


20 minutes later came back and it looked like the airwash air was acting as a secondary air inlet as well igniting fumes up against the glass (img below). STT up around 650,

20220103_152829.jpg


I closed the primary 100%. 5 minutes later the ignition on the glass had stopped and STT topped out at 675 F. Images below. And there looked to be either steam or smoke coming from the chimney.

20220103_153050.jpg


20220103_153933.jpg


If i shut the air down quicker should i be able to control the max temperature better? My concern is putting in a full load vs this load (maybe half load) and not being able to keep it from hitting 800.

I'm having a hard time telling when I should turn down the air. I feel like I either turn it down too quickly and it backpuffs or I wait too long and I'm playing catch up to ward off a runaway.
 
3 large splits about 1.5hrs into the load, primary air open about 1/16". 24 degrees outside. This has been pretty typical of what comes out of the chimney at this level:
20220124_213601.jpg


Fire:
20220124_213841.jpg


STT 590
Flue single wall 340
 
thanks for all the thorough info. I think our stoves are very similar, just different exterior design. but looking at your photos i have all the exact same controls, cat gauge is identical, secondary holes are identical, same firebox size and BTU rating, etc.

"20 minutes later came back and it looked like the airwash air was acting as a secondary air inlet as well igniting fumes up against the glass (img below). STT up around 650"

I have noticed this too. Sometimes my secondaries are big flames near the top of the glass that shoot up over the baffle, vs, sometimes i have the secondaries that shoot out of the row of secondary holes in the top rear of the stove. I don't think this is reason to panic. my current hypothesis is that it depends on the load of wood i have put in, if it sits toward the back, or toward the front, and therefor how the gases are routing through the firebox. 650 STT is about as high as i go. Despite it sometimes getting a bit ahead of me and making me nervous, i've actually never had it go above that. Close the air all the way down, i have a flue damper i might shut halfway (45 degree angle) if i'm really worried, but overall i don't think these stoves are prone to over fire. with the air closed down fully, i think it's pretty air tight (in terms of the new EPA stoves). I actually found this data somewhere in one of their test reports one time, it tells you exactly the square inches of air intake when it is 100% open vs 100% closed.

"I'm having a hard time telling when I should turn down the air. I feel like I either turn it down too quickly and it backpuffs or I wait too long and I'm playing catch up to ward off a runaway."

I have this issue too. earlier in the season i had more backpuffs as i was learning, but since then it is much less of an issue. I still shut down the air too quick sometimes and snuff the flame, but no more of the big bang backpuffs that shoot out smoke when it ignites. Early on i was using the flue damper a lot to try and get low/slow burns, but i don't do that much anymore. I basically never use the damper unless i'm worried about a runaway. Anyways, i think having a damper closed makes the backpuff quite a bit worse. if i am getting backpuffs i open the air back up, get flames, and let the fire break in with aggressive flames for another 5 mins before i attempt to close down again. here again, i think the way i load the wood into the firebox has a large part to play. If there is good airflow between the splits, i rarely snuff out the flame. if the splits all pack into one big block in there, more likely to snuff out the flames and get a backpuff. With good draft and dry wood and the damper open however, sometimes the stove bounces back and forth between no flames and dancing secondaries and it's not a problem.
Have you had glowing cats yet? On several occasions, if i snuff the flame out, i will get glowing orange cats (kinda hard to see cause of the baffle, have to look in at just the right angle/height). One time it was so aggressive the internal firebox around the cats was glowing too. As soon as flames come back in the firebox though, the cats immediately cool right down, within seconds, kinda cool to watch.
 
thanks for all the thorough info. I think our stoves are very similar, just different exterior design. but looking at your photos i have all the exact same controls, cat gauge is identical, secondary holes are identical, same firebox size and BTU rating, etc.

"20 minutes later came back and it looked like the airwash air was acting as a secondary air inlet as well igniting fumes up against the glass (img below). STT up around 650"

I have noticed this too. Sometimes my secondaries are big flames near the top of the glass that shoot up over the baffle, vs, sometimes i have the secondaries that shoot out of the row of secondary holes in the top rear of the stove. I don't think this is reason to panic. my current hypothesis is that it depends on the load of wood i have put in, if it sits toward the back, or toward the front, and therefor how the gases are routing through the firebox. 650 STT is about as high as i go. Despite it sometimes getting a bit ahead of me and making me nervous, i've actually never had it go above that. Close the air all the way down, i have a flue damper i might shut halfway (45 degree angle) if i'm really worried, but overall i don't think these stoves are prone to over fire. with the air closed down fully, i think it's pretty air tight (in terms of the new EPA stoves). I actually found this data somewhere in one of their test reports one time, it tells you exactly the square inches of air intake when it is 100% open vs 100% closed.

"I'm having a hard time telling when I should turn down the air. I feel like I either turn it down too quickly and it backpuffs or I wait too long and I'm playing catch up to ward off a runaway."

I have this issue too. earlier in the season i had more backpuffs as i was learning, but since then it is much less of an issue. I still shut down the air too quick sometimes and snuff the flame, but no more of the big bang backpuffs that shoot out smoke when it ignites. Early on i was using the flue damper a lot to try and get low/slow burns, but i don't do that much anymore. I basically never use the damper unless i'm worried about a runaway. Anyways, i think having a damper closed makes the backpuff quite a bit worse. if i am getting backpuffs i open the air back up, get flames, and let the fire break in with aggressive flames for another 5 mins before i attempt to close down again. here again, i think the way i load the wood into the firebox has a large part to play. If there is good airflow between the splits, i rarely snuff out the flame. if the splits all pack into one big block in there, more likely to snuff out the flames and get a backpuff. With good draft and dry wood and the damper open however, sometimes the stove bounces back and forth between no flames and dancing secondaries and it's not a problem.
Have you had glowing cats yet? On several occasions, if i snuff the flame out, i will get glowing orange cats (kinda hard to see cause of the baffle, have to look in at just the right angle/height). One time it was so aggressive the internal firebox around the cats was glowing too. As soon as flames come back in the firebox though, the cats immediately cool right down, within seconds, kinda cool to watch.
If the cats are in the active range and I snuff out the flames the cats do glow. The cat thermometer rises quickly toward the upper end in these cases.

Do you load wood on top of the primary air inlet ? Or do you keep it behind that?
 
Both. But mostly over the top. Usually the coals and ash are piled up high enough in the bottom of the stove that they are level with the top of the dog house (primary inlet). So if i put splits behind the inlet i find they roll or slide up against the face of the inlet and block it. Instead i put my forwardmost split over the top of the doghouse lip and the coal bed, with a little hole made in front of the air inlet. so air can get in and under the load. When in doubt, i also find that one or two small sleepers going N/S under the load really helps everything ignite quicker and better. Only problem with that is it means less space to load up.
I have had a few loads of 12" long splits loaded N/S and i am very intrigued. It lights and burns beautifully, great air flow. It's also the fullest i can ever get the stove, literally solid packed firebox. Only problem is it does seem prone to over firing. I am bucking some Oak at 12" right now to split and stack, in a couple years when it's ready i will run a couple cord through N/S and see which i prefer.

What kind of burn times do you get?
 
Both. But mostly over the top. Usually the coals and ash are piled up high enough in the bottom of the stove that they are level with the top of the dog house (primary inlet). So if i put splits behind the inlet i find they roll or slide up against the face of the inlet and block it. Instead i put my forwardmost split over the top of the doghouse lip and the coal bed, with a little hole made in front of the air inlet. so air can get in and under the load. When in doubt, i also find that one or two small sleepers going N/S under the load really helps everything ignite quicker and better. Only problem with that is it means less space to load up.
I have had a few loads of 12" long splits loaded N/S and i am very intrigued. It lights and burns beautifully, great air flow. It's also the fullest i can ever get the stove, literally solid packed firebox. Only problem is it does seem prone to over firing. I am bucking some Oak at 12" right now to split and stack, in a couple years when it's ready i will run a couple cord through N/S and see which i prefer.

What kind of burn times do you get?
I also found that happening with splits rolling into the inlet unless I was super careful with loading. Wasn't sure if I could load on top of it or not so I've only been getting 2 rows of 2 large splits in the box and maybe a medium sized split in an open area depending how Jenga goes. With that kind of load (mostly white ash) I've seen 10 hrs where there's enough coals to throw kindling in then get a fire going again. Thats peaking at 625 stt and cruising around 575. If there's a quick off gassing event it ends up being much less. I'm guessing if I could add 2,3 more splits I'd easily be over 12 hr mark with a usable bed of coals.

What kind of burn time are you seeing?

I use the sleepers on cold starts even if the ash is built up to have a trench just so I don't have to worry about it. The trench works for reloads though assuming there are enough coals.

Also, the 600 max stove top temp that hearthstone provided has to be pure CYA on their part. With a big enough load I'm pretty sure it's almost impossible to keep the stove below 600 peak. The stove starts to really throw heat 600+.
 
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I was unaware of the 600 max recommendation from hearthstone. I have just been going with my STT gauge which i think has either 650 or 700 as "over fire" range. I have never gone above that. But 600 to 650 is pretty common at peak.
For burn times i have been getting 5 to 7 hours - as in, active secondaries and then hot wispy flaming coal bed, STT above 300 and blowing heat into the room (i have the blower kit). As far as enough coals to rake them around and get a relight off of them, that is easily 10 hours, in some cases more like 16. But i don't think that's any magic from hearthstone, I think that is just coals being insulated in ash. I do think their "Heat Life 24 hour" claim is true, if you consider "Heat Life" to just mean a warm stove top. I load up at night around 9 pm, and at 6am the next day i always have a warm stove top, usually around 200 degrees on STT. I have definitely come back the following afternoon and had the stove top warm to the touch.
I heat from the basement, so i kind of need the STT to be in that 400 to 650 range really throwing heat, to do much for me, and for that range I haven't been able to really get beyond 6 or 7 hours.
 
I have this stove as well, can others with this confirm what your stove pipe temperature is? I get near the high end of the catalyst range but my flue temp about 12 inches up stays pretty low 300 max (it is a magnetic amazon thermometer which I am replacing though). Anyone else experience this?
 
I get near the high end of the catalyst range but my flue temp about 12 inches up stays pretty low 300 max.
Is the stovepipe single-wall or double-wall?
 
I have this stove as well, can others with this confirm what your stove pipe temperature is? I get near the high end of the catalyst range but my flue temp about 12 inches up stays pretty low 300 max (it is a magnetic amazon thermometer which I am replacing though). Anyone else experience this?
Replied to your post but I see 275-450+ depending on the stage of the fire. Single wall 12" from stove with IR gun
 
some of this info has been posted in a different thread but want to keep this comprehensive for this stove so adding it here.

confirmed that my chimney setup is as follows:
  • rear exit into adjustable elbow with 4" rise, ~1ft length
  • uninsulated tee with 18" snout, had 1/4" rise per foot
  • 16' 5.5" uninsulated liner
according to the manual it should be:
  • 16.5' 6" insulated liner
i'm upgrading the following:
  • ~15.5' 6" insulated 316ti liner
  • insulated tee/snout
  • 5' Class A
So I should have effectively 4 ft more chimney height

Smoke rollout was my main concern, but I'm hoping that this will solve the problems I saw with the air wash igniting secondary combustion resulting in high STT. My thought process being; as I closed the primary air the total volume of gases going up the chimney decreased. This caused the flue to begin to cool (not insulated), which reduced the draft causing a reduction in velocity of the gases. Even though the STT and gasses were hot there just wasn't enough volume to keep the flue warm. Everything still went up the chimney, but there wasn't a lot of movement, so the stove got hot, the wood off gassed and any air introduced caused secondary combustion.
 
total chimney height is now ~21.5'; hoping this along with the insulated 6" liner fixes the draft issues I had last year

20221002_110903 (2).jpg
 
That should make a notable improvement. Keep us posted.
 
That should make a notable improvement. Keep us posted.
haven't really got a chance to test out the setup below 39 degrees. only had 2 actual cold starts (beyond the break-in fires) and no hot reloads.

the only thing i feel confident in commenting on at this point is smoke rollout during cold starts. i've been warming the flue with a heat gun prior to starting the fire, lighting a top down fire using newspaper, cracking a nearby window open 2".
  • on initial lighting with the door wide open and primary 100% open the flames and any smoke from the newspaper seems to be sucked up the flue and i can't smell anything
  • as the kindling begins to light any smoke that is released looks like it is going to get pulled up the flue but some of it starts to swirl up around where the baffle/air wash and I can smell smoke and see some escape
  • with the previous setup any smoke from the newspaper would rollout the door
I believe primary air feeds the air wash on this stove; so I'm wondering if I were to shut the primary during a cold start when the door is open would I resolve this issue of smoke turbulence from the air wash and thus no smoke rollout? Obviously when i close the door to "just cracked" I would open the primary inlet 100%. thoughts would be appreciated.
 
haven't really got a chance to test out the setup below 39 degrees. only had 2 actual cold starts (beyond the break-in fires) and no hot reloads.

the only thing i feel confident in commenting on at this point is smoke rollout during cold starts. i've been warming the flue with a heat gun prior to starting the fire, lighting a top down fire using newspaper, cracking a nearby window open 2".
  • on initial lighting with the door wide open and primary 100% open the flames and any smoke from the newspaper seems to be sucked up the flue and i can't smell anything
  • as the kindling begins to light any smoke that is released looks like it is going to get pulled up the flue but some of it starts to swirl up around where the baffle/air wash and I can smell smoke and see some escape
  • with the previous setup any smoke from the newspaper would rollout the door
I believe primary air feeds the air wash on this stove; so I'm wondering if I were to shut the primary during a cold start when the door is open would I resolve this issue of smoke turbulence from the air wash and thus no smoke rollout? Obviously when i close the door to "just cracked" I would open the primary inlet 100%. thoughts would be appreciated.
I usually shut the door to just a crack, quickly after lighting the newspaper, so I don’t have smoke rollout at this phase. I have smoke rollout if I’m not super careful about when I time my reload.
Your theory about the air intake might be worth trying - rather than some percentage of the draft sucking air in through the air intake, 100% would be pulling air in through the front door? Maybe.
 
I usually shut the door to just a crack, quickly after lighting the newspaper, so I don’t have smoke rollout at this phase. I have smoke rollout if I’m not super careful about when I time my reload.
Your theory about the air intake might be worth trying - rather than some percentage of the draft sucking air in through the air intake, 100% would be pulling air in through the front door? Maybe.
Yes that's normally what I've done. But every once in awhile a cold start fails to take off and then I either have smoke rollout, try to establish it while the door is cracked, or wait for it to die completely.

And that's the idea, I read a post here that doing something like that fixed a smoke rollout problem. It's in the 70s today tho so I'll have to wait to try it.
 
Yes that's normally what I've done. But every once in awhile a cold start fails to take off and then I either have smoke rollout, try to establish it while the door is cracked, or wait for it to die completely.
Yes, I’ve experienced the same issue. If that first attempt doesnt take off, you’re in big trouble. Opening the door at all is a big smoke rollout at that point. Same thing if a reload doesn’t take off, can’t open the door cause you’ll get tons of smoke.
I actually use fire starters for this reason. I probably don’t always need them, but I can’t take the chance that that first light up doesn’t take, cause I won’t be able to open the door fully again without getting smoke.
 
Yes, I’ve experienced the same issue. If that first attempt doesnt take off, you’re in big trouble. Opening the door at all is a big smoke rollout at that point. Same thing if a reload doesn’t take off, can’t open the door cause you’ll get tons of smoke.
I actually use fire starters for this reason. I probably don’t always need them, but I can’t take the chance that that first light up doesn’t take, cause I won’t be able to open the door fully again without getting smoke.
FWIW, I lit a top down fire tonight. It's 43 F outside, no wind. There was an unusual amount of smoke in the firebox, maybe because I threw some bark in there. Anyway, I had the primary closed and the door wide open and the smoke/flames went up the flue. Only when I started to close the door did the smoke get perturbed and look like it may escape out of the box. Once the door was "cracked" I opened the primary 100%. Fire continued to take off. At least for the first attempt it looks like this may be a solution.
 
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Repeated the above; same results. Except I didn't put bark in the box and there was significantly less smoke on cold start.

I performed a reload. STT was 300-325F. I opened primary 100% and opened by-pass for 5+ minutes. I cracked the door ~1", closed the primary 100%, and slowly opened the door. I moved coals around and saw some fly ash escape the firebox. I could also smell "fire". Didn't necessarily smell like smoke. Maybe I should have opened the door slower/in more stages, but I don't think this solved the issue on hot reloads.

Later on in the run I did have what would have previously resulted in a back-puff with the old chimney, but no smoke escaped the stove with the new setup.
 
With the new chimney setup the stove is definitely reacting differently to air inlet changes. In the past I had to keep primary air open to ensure the fire wouldn't get snuffed out. I think I have to start closing it down quicker now, but I'm not sure what I'm looking for @begreen
  • Does the entire wood load need to be charred/on fire prior to closing down the primary?
  • How do you gauge "I need to close the primary more"? By the flames lapping the baffle or the flames being drawn up/over the baffle?
  • Should it be possible to load up the stove full and mitigate the "gas-grill effect" and instead just have dancing secondaries?