Super 27 running very hot

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here
I plugged my air intake last night. Loaded the stove and it was just ripping through it at 1100° flue temp. So I plugged it. Woke up to actual coals today. So I definitely slow the burn and dropped the flue Temps. However I'm at work now and the wife is starting the fire today. It will take some getting used to. She says it's taking far longer to establish itself. I'll keep experimenting. I don't want to waste wood. I want longer more efficient burns. A key damper may be in my future. That way I can let the stove be and just regulate with the damper.
 
I plugged my air intake last night. Loaded the stove and it was just ripping through it at 1100° flue temp. So I plugged it. Woke up to actual coals today. So I definitely slow the burn and dropped the flue Temps. However I'm at work now and the wife is starting the fire today. It will take some getting used to. She says it's taking far longer to establish itself. I'll keep experimenting. I don't want to waste wood. I want longer more efficient burns. A key damper may be in my future. That way I can let the stove be and just regulate with the damper.
Thanks for the info @Split . Did you plug the welded hole? I've got 2 holes next to the air inlet plate.
 
I wonder if a piece of foil tape over half of the hole may help?

What temps do you have outside right now?
 
If you can get to it, slide a magnet on/off the hole as needed...
 
Could the wood be too dry? I’m beginning to see this in other threads with other non cat owners. These stoves are tested with 20% wood on a 15’ chimney. 8-15% wood is super dry and once going likes to off gas all at once. I know I see this with my stove especially if I use smaller splits. I’ve compensated by block my boost air and using larger splits. I also no longer strive to get 3 years ahead on my wood supply but I’m burning Aspen and it’s ready to burn in 6 months.

I bet your Elm is much dryer than the Maple. Are you sure it’s Hard Sugar Maple? I know Red and Silver drys much faster than Sugar and can see it also getting too dry.
 
@Todd Thanks for your reply.

I'm pretty sure the dryness of the wood is playing a big part. I tried mixing in some birch that was closer to 18-22% and that slowed down the secondary burn a bit but it still gets going pretty good even with the air inlet closed all the way down.

It's hard maple, no red or silver maples on our property. I could be off on my timing a bit on when it was split but it's dry around 15% give or take. And yes, the elm is even dryer. We have some white ash as well that's super dry too. I'll have to keep experimenting with the wood. We have some white ash that we just split that was standing dead. I should be able to mix that in after a couple months. It tested at 25% when we split it...we split that a little larger than normal also to try.

Do you have any trouble starting fires with the boost inlet plugged?

I really like the stove but it would be even better if I could just slow it down a bit on the secondary burn.

Thanks again.
 
  • Like
Reactions: Todd
No problem at all starting fires with my boost air closed but I have a different stove and straight up 22’ chimney. I don’t know how your stove will react to closing it but it’s worth a try. You have that EBT for your secondary air and I wonder how you can tell if it’s working properly or if would open more if you modified any primary air? Also have you checked your primary air slide? I recall someone with a PE that had some obstruction pushing the slide up causing it not to close completely.
 
I'm going to pick up a magnet and try covering the boost hole as other have suggested.

I'm fairly certain the EBT is working properly. It's very clear that the secondary burn is happening when looking at the baffle and tubes. There's also no smoke coming out the chimney. Stove top temps are correct also. I'm sure it is operator error, dry wood, too hot of coals when reloading or combination of everything. But I don't know for sure as I'm new to these EPA stoves. I don't know what you would do if you had one of these with a very tall chimney and very cold outside temps though. They must draft like crazy and chew through a ton of wood.

Regarding the primary air slide, the 2020 PEs are different. The air inlet plate fully covers the air inlet now when closed all the way but there is a 1/2" hole next to it that is always open. It's my understanding that hole should never be covered, but I may try covering part of it if it comes to that point. Sounds like people were bending the plate to close more on the previous models.

As always, there is a ton of good information here. Very helpful and lots of good suggestions. I'm going to keep experimenting and will report back in a couple weeks as I try different things.
 
  • Like
Reactions: sixer and Todd
Hey Everybody, I thought it would be helpful to upload a video of what I'm experiencing on the secondary burn. This was at the peak (sorry its short, I could not get the longer one to upload). Stove top temp hit just under 700 (please disregard the magnetic temp you see at the base of the stove pipe, I am not using that one. There is a second magnetic thermometer on the top of the stove in the center).

Wood was a mix of maple, elm and birch. Firebox was about 3/4 full started from coals (coals were burned down more than normal before reloading).

It is hitting this point after every reload at some point. Sometimes it's an hour, sometimes two. Air inlet is closed all the way down. This load will be burned down to coals in about 3 hours total, from time of reload.

Does this look normal for you PE owners out there or is it taking off to much on me?
 
Hey Everybody, I thought it would be helpful to upload a video of what I'm experiencing on the secondary burn. This was at the peak (sorry its short, I could not get the longer one to upload). Stove top temp hit just under 700 (please disregard the magnetic temp you see at the base of the stove pipe, I am not using that one. There is a second magnetic thermometer on the top of the stove in the center).

Wood was a mix of maple, elm and birch. Firebox was about 3/4 full started from coals (coals were burned down more than normal before reloading).

It is hitting this point after every reload at some point. Sometimes it's an hour, sometimes two. Air inlet is closed all the way down. This load will be burned down to coals in about 3 hours total, from time of reload.

Does this look normal for you PE owners out there or is it taking off to much on me?
View attachment 303490
Mine burns like that. I'm sure once you get your flue probe it will be high like mine.
 
Looks a little lively but to be expected with really dry wood.

When you reload do you rake all the coals as far forward as you can? Also load the splits all the way to the back firebricks. This should help create a front to back cigar type burn.
 
  • Like
Reactions: sixer
Looks a little lively but to be expected with really dry wood.

When you reload do you rake all the coals as far forward as you can? Also load the splits all the way to the back firebricks. This should help create a front to back cigar type burn.
I do rake the coals forward and load the splits all the way to the back. I could probably do a better job of separating coals and ash and getting all or more of the coals to the front.

After that fire, I did have enough coals to start a fire this morning no problem about 9 hours later so I can't complain about that.

This morning, I loaded some larger splits of white ash that were closer to 20%. One might have been over 20% cause it was sizzling a little bit and smoking. There was a noticeable difference. I could not turn down nearly as quickly and it took a lot longer to get the secondary burn going and eliminate the smoke from the chimney (I was turning down too quickly). I think the maple and elm I am burning is just super dry and causing the fire to take off. Burning much better now with the secondaries going and not roaring hot. I'm going to try to do a better job of mixing some of that all together and be more diligent of turning down very quickly when burning the really dry stuff.

@Split What wood are you burning? Have you put a moisture meter on it when split?

Thanks for taking a look at the video.
 
  • Like
Reactions: Todd
While others have more experience with this type of stove, I wonder what the fire looks like half an hour in (you said the video was an hour after reloading), and how long this phase (video) lasts?
 
While others have more experience with this type of stove, I wonder what the fire looks like half an hour in (you said the video was an hour after reloading), and how long this phase (video) lasts?
The secondary burn had started a half hour in but the fire was not nearly as lively as in the video. How long this lasts depends on how much wood is in the firebox. But when it really gets going it will be down to coals in 2-3hours.
 
It sounds like covering the boost air port is helping a lot. Is your wife starting the fire on a hot coal bed or from scratch? If she is starting the fire from morning hot coals, then she may need to change methods slightly. Maybe try laying down some kindling "sleepers" N/S for the bigger splits to rest on? That will let more air get under the wood for a quicker start.

If she is starting fires from start, then a fire starter like a chunk of SuperCedar, can make starting a breeze, even without kindling.
 
Would too much combustion air coming into the stove do anything to cause a lively fire?

I do not have outside air kit installed and use room air through the knock out on back of the pedestal ( the manual was not super clear on this but it was my understanding that this should be open for room air).

From the manual..
"Room air supply - The stove will draw its air from the room through the opening in the Ash Box Enclosure and into the firebox intake."

Was I correct to remove the cover on the rear of the pedestal?

Thanks.
 
Yes, too much air will cause a lively fire. I dont think the cover on the pedestal would affect this. Your damper should still be untouched.
 
Thank you but to clarify, it is correct to remove the rear cover for room air?
I believe so. I have the Super Insert LE 2020 EPA model. I removed a metal piece from the front per the instruction manual for using room air. For the most part I find that the draft control has the dynamic range that I need to control the fire.

However I too have had the fire kind of "run away" on me, but only under certain conditions. It was a hot reload before bed time and there were still quite a bit of hot coals. I don't remember if I raked them forward. The STT was maybe 250-300F at time of load, hotter than usual. I packed it pretty good, 7-8 very dry hardwood splits. I opened the draft control all the way to get things started, then ratcheted it down over 30 min or so. Around then it was really cooking. STT close to 800F, draft all the way down, blowers on max, the flames still cruising, secondaries going strong. So I got onto this forum and read as much as I could for about 2 hours. By then it was slowing down and the temp started dropping. In the end I determined:
  • 800F is pretty hot, but probably ok and not quite an overfire. (usually the stove runs 600-700F max STT)
  • I turned the draft down too slowly for the conditions.
  • The wood was very dry.
  • I loaded too many splits on coals that were too hot and possibly didn't rake them forward.
  • I was going to be very tired in the morning.
My takeaway: Operating a wood stove is as much an art as it is a science. It can be a challenge, each fire is different, and that's what makes it fun.

In your case it does seem like maybe there's too much air getting in. Is it possible for you to turn the draft control down too early and get the wood to smolder, or will you always get flame? If you can get things cruising with the draft nearly all the way down that might indicate an air leak. On mine it's imperative to have the draft almost full open to get things going. For reference, it's got 25' of 6in liner in a masonry/terra cotta lined chimney.
 
Thank you but to clarify, it is correct to remove the rear cover for room air?
It was not necessary. That knockout is for connecting to the outside air.

Did the probe flue thermometer get put in? That will help with guidance.
 
It was not necessary. That knockout is for connecting to the outside air.
Not according to the manual...

[Hearth.com] Super 27 running very hot
 
That looks like it is from an old manual. This is what my copy of the Super LE manual says:

Room air supply - The stove will draw its air from the room through the opening in the Ash Box Enclosure and into the firebox intake.

The only mention of removing the rear knockout is above that line in the manual in the instructions for installing an outside air kit.
 
I haven't looked closely at the new Super or Summit, but in the past, these stoves did not have a tight ducted connection to the air intakes on the stove. They put air into the leaky enclosure of the ashpan tray or the pedestal. Neither of these is gasketed or airtight. I believe this is to provide an air break to the outside air to avoid the OAK becoming a chimney but that is just my conjecture.

FWIW, I see no harm in removing the knockout.
 
Hi @begreen, I too looked at the super LE manual and you are correct. However the OP says he has a Super 27. The snip I posted was from that manual. Given the problem he's describing though, it seems possible there's too much air getting in somewhere...