Super 27 running very hot

[TomMcDonald]

A hot enough fire will melt aluminum foil jammed into the front boost hole. Or maybe the fairies steal it. They are kleptos.

Has never happened to me.

 

[flamontagne]

Hi Begreen and Woody Stover,

Try starting to turn down the air when the stove pipe temp is 400º and don't turn it down all the way, just until the flames start to get lazy. Then wait for the flames to regain strength and close it down some more until the flames get lazy again. Also, remember that the air control is not linear. Most of the control is in the last inch of movement.

During the day, you can go out and look at the plume to determine how cleanly it is burning. Now, steam is released at the beginning of the load, but it has a different look than smoke, which looks darker and heavier.
I haven't run the secondary stove I have access to enough yet to understand what goes on, but I'm wondering what happens if you shove the coals to the back, where there's ash under most of the load instead of coals. Does the fire progress in a more controlled manner if it has to work its way "upstream," from back to front?
How about with a top-down fire started in the back?
I guess a lot depends on the wood you're using as well, since dense woods I use seem to catch and burn at a slower, more controlled rate.

I tried controlling the air intake as begreen suggested and I raked the coals at the back of the stove as Woody Stover suggested. The same thing happened. The fire was under control for a while (perhaps for 45 minutes or more) then the second combustion went into high gear and at this point it seems there is nothing I could do to calm it down (air intake was already turned all the way down). I took a small video to show you how it looks when it kicks in. Most of the wood in the stove is birch (round logs).

It's strange because if you told me to trust only my eyes I would probably tell you that this fire looks just fine... but the surface temperature on my single wall stove pipe seems to indicate a problem.

 

[begreen]

The video does not appear to have loaded. The file size may be too large. High flue temps with a normal fire often indicate strong draft. In that case, a key damper is a good way to reduce the draft and flue temps.

 

[Woody Stover]

fire was under control for a while (perhaps for 45 minutes or more) then the second combustion went into high gear and at this point it seems there is nothing I could do to calm it down (air intake was already turned all the way down)....I thought the issue was excessive draft since my chimney is very tall (37 ft)....wish I could load it up fully without having the fire goes nuts

Yeah, the amount of wood gassing is going to increase as the load progresses, particularly if you are loading softer woods. What species of wood do you have? Larger splits of dense woods gas more gradually than smaller splits of lightweight wood.
In that tall chimney, do you have a liner all the way to the top? If so, draft will be strong.
In that case I would try putting in two dampers, stacked at the bottom of the connector pipe where you can reach them during installation. Now, you may have to open the air a little more later in the burn to keep the burn clean, I don't know. You'll have to keep an eye on the plume as the burn progresses. Sure, you'll have to make air adjustments, but maybe you can load more wood this way, yet still keep the burn under control.

 

[flamontagne]

The video does not appear to have loaded. The file size may be too large. High flue temps with a normal fire often indicate strong draft. In that case, a key damper is a good way to reduce the draft and flue temps.

Strange, I don't know why the video isn't loading. If you click on the attachment and save the mp4 to your computer, it might work. Well, it did for me.

My local Pacific Energy dealer told me he was not authorized to install a key damper on my pipe due to some construction regulations in my province, as it supposedly increase the risk of having carbon monoxide in the house. Seems like a stretch to me. With the strong draft I have it feels like a key damper would be a wonderful solution to my problem.

Yeah, the amount of wood gassing is going to increase as the load progresses, particularly if you are loading softer woods. What species of wood do you have? Larger splits of dense woods gas more gradually than smaller splits of lightweight wood.
In that tall chimney, do you have a liner all the way to the top? If so, draft will be strong.
In that case I would try putting in two dampers, stacked at the bottom of the connector pipe where you can reach them during installation. Now, you may have to open the air a little more later in the burn to keep the burn clean, I don't know. You'll have to keep an eye on the plume as the burn progresses. Sure, you'll have to make air adjustments, but maybe you can load more wood this way, yet still keep the burn under control.

I think you're on to something here. Most of the wood I have this year is unsplit birch (I think it's gray birch). To my understanding birch is a somewhat lightweight wood that burns quite fast compared to maple or oak.

Yes the draft is strong. I have a 6 inches stainless steel liner that goes all the way to the top. The liner is inserted into an interior masonry chimney. The wood stove is located in the basement. I have a single wall pipe about ~4 feet in height straight, then a short elbow that goes straight to the chimney.

 

[begreen]

My local Pacific Energy dealer told me he was not authorized to install a key damper on my pipe due to some construction regulations in my province, as it supposedly increase the risk of having carbon monoxide in the house. Seems like a stretch to me. With the strong draft I have it feels like a key damper would be a wonderful solution to my problem.

A key damper will still allow at least 20% of the smoke to pass even when fully closed. Homes with stoves in a negative pressure zone are often more at risk of draft reversal.
Has the boost air port been blocked with a magnet or some metal tape?

 

[Woody Stover]

The video does not appear to have loaded. The file size may be too large. High flue temps with a normal fire often indicate strong draft. In that case, a key damper is a good way to reduce the draft and flue temps.

I got a HEVC extension thing from MS to play the .MP4 file in Windows 10. Looks like long flames 4" or more are coming from the wood, which I assume is some Birch rounds, all the way to the baffle holes. Surface meter on single wall is 625. The fire is robust but not roaring..

 

[begreen]

Surface meter on single wall is 625

That is definitely too hot and wasting a lot of heat up the flue.

 

[alber197]

@flamontagne I had similar issues as you as you've read in my previous posts. Plugging the boost hole really helped me. You'll have to relearn the stove cause you can turn it down too much and too quick with that covered but we got the hang of it once we got the flue probe thermometer.

Dry birch will definitely take off super quick in that stove.

We don't have a draft issue but as @begreen mentioned try covering the boost hole. A magnet worked well for me.

 

[Split]

I got a new Super LE installed at the beginning of the month and had a similar problem. I tried covering the "boost air" with a magnet but it didn't help. The second combustion would still eventually go nuclear on me even with the air intake closed to minimum. My surface thermometer located on the pipe would climb to 700 or more and stay there for way too long. I was getting worried I would break something in my brand new wood stove. I thought the issue was excessive draft since my chimney is very tall (37 ft). I called my PE dealer and asked him if he could install a damper on my wood stove pipe just to tame the draft a little. He told me he could not install this as this was against some new building regulations in my province. He told me that a damper would not be necessary anyway and that he doubted the strong draft was the issue.

Finally when I told him I was loading my firebox up to the top of the bricks he interrupted me and told me that it was the problem and that I should stop doing that. He said that the way to go with these stoves was to put 2-3 medium size logs every 5-6 hours and 1 or 2 big round logs for an overnight burn. This surprised me because everwhere I read online people seem to load the firebox as I did before, so I don't know what to think of what he said yet.

Anyway I am now trying this "add little by little" technique and so far I have to say it seems to work great. The stove still gives a lot of heat and I have a controlled burn without overheating. When I reload I wait until the logs are charred and until I see roaring flames everywhere for 5-10 minutes before cutting the air 50% and then a little more until I get a surface temperature (on the pipe) of around 450. Then it sits at that temperature for a while before slowing dropping. Interesting fact I also have a thermometer on the top of my stove and it sits at 650-700, which was the same temperature I had when I loaded my firebox completely. It seems to indicate that I was wasting a lot of heat before.

The original poster on this thread mentioned that he had the nuclear second combustion issue even when he did a small fire, so his problem seems to have another cause than mine. I just thought my experience could help others who have their Super LE burning too hot.

That's awesome and thanks for the input. I too have started to not load so much. I still get great (tolerable) heat and lovely secondaries. I'm so glad you posted because all I ever hear is JAMM IT FULLLLLL That sends my stove to nuclear levels and will cook us out of the house.

 

[alber197]

That's awesome and thanks for the input. I too have started to not load so much. I still get great (tolerable) heat and lovely secondaries. I'm so glad you posted because all I ever hear is JAMM IT FULLLLLL That sends my stove to nuclear levels and will cook us out of the house.

We have experimented with this quite a bit. Obviously if you put less wood in you get less heat and BTUs but you will have to load it more often.

For us, it depends the outside temperature. If it's negative outside we can't get away with only putting a few splits in or we have to load it every few hours. When it's warmer outside, we will put a few splits in and let it go out. Coals last along time in the super and fire is easily relit if needed.

You have to be very diligent when you first load it and don't let it go for too long with the intake wide open. A flue probe thermometer helps alot as others have mentioned.

 

[Split]

Hi Begreen and Woody Stover,






I tried controlling the air intake as begreen suggested and I raked the coals at the back of the stove as Woody Stover suggested. The same thing happened. The fire was under control for a while (perhaps for 45 minutes or more) then the second combustion went into high gear and at this point it seems there is nothing I could do to calm it down (air intake was already turned all the way down). I took a small video to show you how it looks when it kicks in. Most of the wood in the stove is birch (round logs).

It's strange because if you told me to trust only my eyes I would probably tell you that this fire looks just fine... but the surface temperature on my single wall stove pipe seems to indicate a problem.


View attachment 306396

Mine always burns like that. Looks great. And with only a few splits that'll go down in an hour or less. You're burning clean and will have no creosote.

I'll stick to the 'less splits per load' for a while and see how it fairs.

I find if I block the boost port with a magnet it doesn't burn ss well. I don't need creosote build up.

 

[begreen]

That's awesome and thanks for the input. I too have started to not load so much. I still get great (tolerable) heat and lovely secondaries. I'm so glad you posted because all I ever hear is JAMM IT FULLLLLL That sends my stove to nuclear levels and will cook us out of the house.

With so many variations in stove installations, stove location, floorplans, ceiling heights, home characteristics, etc. there is no universal, one solution that fits all. If the stove is a bit oversized for the install location then definitely don't over fill it, or use a fan blowing air from a cooler part of the house into the stove room to balance out the heat.

 

[flamontagne]

Hi everyone and thanks for your input.

A key damper will still allow at least 20% of the smoke to pass even when fully closed. Homes with stoves in a negative pressure zone are often more at risk of draft reversal.
Has the boost air port been blocked with a magnet or some metal tape?

Yes I blocked the boost air port but didn't notice a difference. I have since removed the magnet but I may give it another shot just in case.

@flamontagne I had similar issues as you as you've read in my previous posts. Plugging the boost hole really helped me. You'll have to relearn the stove cause you can turn it down too much and too quick with that covered but we got the hang of it once we got the flue probe thermometer.

Dry birch will definitely take off super quick in that stove.

We don't have a draft issue but as @begreen mentioned try covering the boost hole. A magnet worked well for me.

I noticed that the problem starts happening only when i am stacking my birch logs. When all the logs are directly put on the base of the firebox everything is fine. Also, the issue happens less often on cold starts. It's only when reloading that I have to be super careful with the amount of wood I put in it.

That's awesome and thanks for the input. I too have started to not load so much. I still get great (tolerable) heat and lovely secondaries. I'm so glad you posted because all I ever hear is JAMM IT FULLLLLL That sends my stove to nuclear levels and will cook us out of the house.

Yes and I don't enjoy the feeling of not being able to do anything once it takes off. I mean I love the EPA stoves because they're incredibly efficient but I don't like being prevented from closing the air completely if things go too intense. When it happens all I can do is look at my thermometer and hope it stops climbing soon.

The Super is a different beast than my old stove that's for sure! I'm still glad I made the switch though as the new one is much more efficient and burns so much cleaner. Plus the old one didn't have a glass and I'm the kind of guy who can look at fire for hours wihout getting bored. lol

We have experimented with this quite a bit. Obviously if you put less wood in you get less heat and BTUs but you will have to load it more often.

For us, it depends the outside temperature. If it's negative outside we can't get away with only putting a few splits in or we have to load it every few hours. When it's warmer outside, we will put a few splits in and let it go out. Coals last along time in the super and fire is easily relit if needed.

You have to be very diligent when you first load it and don't let it go for too long with the intake wide open. A flue probe thermometer helps alot as others have mentioned.

That's the thing. Right now I can get away with putting only a few splits at a time but it is pretty mild these days. Where I live we sometimes get -10, -20 (farenheit) or even less. During these days I'd like being able to load the stove a bit more. I will give another try and cover the boost air port with a magnet.

I'm starting to understand this stove better. Hopefully by the end of winter I'll have it figured out

 

[begreen]

I noticed that the problem starts happening only when i am stacking my birch logs. When all the logs are directly put on the base of the firebox everything is fine. Also, the issue happens less often on cold starts. It's only when reloading that I have to be super careful with the amount of wood I put in it.

Try burning down the coal bed further by placing just a skinny split on top of the coals and opening up the air to about the 50% mark.

Then, reload and take a picture before closing the stove door so that we can see what you have loaded.

 

[flamontagne]

Try burning down the coal bed further by placing just a skinny split on top of the coals and opening up the air to about the 50% mark.

Then, reload and take a picture before closing the stove door so that we can see what you have loaded.

Hi begreen,

This morning I managed to revive the fire from the previous night. Coal bed was definitely not too hot. I put some kindlings, 4-5 small birch logs and stack 2 medium logs on top. I forgot to take a picture of the load but I promise I will on my next reload!

Same problem happened. I closed down the air intake after 10 minutes (when pipe temp was between 350-400). Fire was nice and stable for 20-30 minutes then it took off. Pipe temperature went into the 600s for a while then slowly decreased to a more reasonnable number. I think I really need a key damper in that chimney.

 

[Draughts15]

I have the Super Classic LE and love this stove. I've only loaded maybe 3/4ths full once and tightly packed as this stove does burn hot and i'm afraid of an overfire.

I've recently discovered loading my stove with splits in a U shape. Coals raked to the front, I have splits on the bottom with smaller splits on the bottom outside edges and two large splits on top of the smaller, one on each side of the firebox since these burn last and this gets it nice and hot. We were below zero in temps and I was able to get our living room and house to a toasty 75. My flue reaches 650 tops. If I get a little worried I turn the blower on low and it keeps the flue in check. I let it go once without the blower just to see how hot it would get and it didn't get above about 675 even without the blower and air closed about 90%. Attached are a couple pictures. These are from an 8pm load and 730a relight. Almost 12 hours. Ive also been able to get hot coals in the ash almost 14 hours later. Flue temp was around 200 still.

 

[flamontagne]

Try burning down the coal bed further by placing just a skinny split on top of the coals and opening up the air to about the 50% mark.

Then, reload and take a picture before closing the stove door so that we can see what you have loaded.

For some reason overfiring seems to be less and less an issue these days. I thought it would get worse since the outside temp keeps dropping and I was worried about the stronger draft in these conditions. I still get a 600f peak (surface temp on the stove pipe) on occasion but when I cut down the air the fire seems to respond a bit more and it calms down a little. Most of the time I'm able to keep the stove pipe temp under 500f.

I'm not sure what is the main cause of this improvement, I guess I'm starting to learn how that stove works a bit more. I feed it a bit less wood than before but not that much. Here is a picture of one of my last reload. The coals were not very hot but the kindlings were enough to ignite the thing.



This load was perhaps a bit too big. I got a slightly uncontrollable fire at one point but it wasn't that bad compared to before (with similar load sizes).

As you can see on the picture below, the birch ignites very easily (perhaps a bit too easily?). This picture was taken 2-3 minutes after the previous one:

I have the Super Classic LE and love this stove. I've only loaded maybe 3/4ths full once and tightly packed as this stove does burn hot and i'm afraid of an overfire.

I've recently discovered loading my stove with splits in a U shape. Coals raked to the front, I have splits on the bottom with smaller splits on the bottom outside edges and two large splits on top of the smaller, one on each side of the firebox since these burn last and this gets it nice and hot. We were below zero in temps and I was able to get our living room and house to a toasty 75. My flue reaches 650 tops. If I get a little worried I turn the blower on low and it keeps the flue in check. I let it go once without the blower just to see how hot it would get and it didn't get above about 675 even without the blower and air closed about 90%. Attached are a couple pictures. These are from an 8pm load and 730a relight. Almost 12 hours. Ive also been able to get hot coals in the ash almost 14 hours later. Flue temp was around 200 still.

View attachment 307278 View attachment 307279

This is great. Thanks for the tips, I will experiment with loading splits in a U shape. It's crazy how long the coal is burning in that stove. I don't know the reason for this but I love it. Like you I am sometimes able to reignite after 12-14 hours.

As for overfiring, I don't have a blower so the only thing I can do when the second combustion goes nuclear is to open the door a little bit to bring some cool air in the stove pipe. I'm not even sure if it helps.

All in all I'm very satisfied with this stove. It's more finicky than my old Drolet but also more efficient.

 

[begreen]

It's good to hear you are making progress. Turning the air down as soon as possible without snuffing out the flame helps. Was the air turned all the way down in the second photo? The pictures are useful. One thing I see right away is that The fire is all rounds and that there is a lot of space between the larger rounds. That's good for quick ignition, but if the goal is to slow down the fire, then pack it tighter. The load is not too big, but it is a bit too loose. Can you split some of the larger rounds and use those splits to fill the gaps?

How long were those rounds drying?

 

[begreen]

Also, try a load E/W. That slows down the burn.

 

[Todd]

Looks like those rounds/splits are too small unless your looking for a short hot fire. If your looking for a more controlled long burn try a full load of larger splits of say 4-8” wide or for a 2 cu ft firebox I’d say 6-7 splits should pretty much fill the box.

 

[flamontagne]

Thanks all for your help! I will try packing the load tighter to restrain the air circulation in the firebox. Most of the wood I have this year is unsplit birch logs which probably doesn't help as no matter their size they tend to ignite very easily.

I'm not sure if an E/W load in this firebox is possible. 16' logs don't fit unless I turn them slightly diagonally.

 

[begreen]

Same problem happened. I closed down the air intake after 10 minutes (when pipe temp was between 350-400). Fire was nice and stable for 20-30 minutes then it took off. Pipe temperature went into the 600s for a while then slowly decreased to a more reasonnable number. I think I really need a key damper in that chimney.

What may be happening is that the draft is sluggish until all the exterior components are fully warmed up. Then, the draft increases dramatically, accelerating the fire too much. If this is the case, the best solution is a key damper in the stove pipe. Keep it open during the warmup phase and close it once the super-draft starts.

It's worth trying burning E/W. That will slow down the fire a bit. The Super Firebox is 18" wide. 16" splits should definitely fit E/W.

 

[flamontagne]

Hello begreen. Oh well now I'm confused because the firebox I have is definitely not 18'' wide. It is a bit less then 16''. I have the Super LE, not the Super Classic. Not sure if this makes a difference?

Thanks for your clear explanations. It seems a key damper would really help.

In the meantime I think I have found a solution to prevent the nuclear second combustion from happening during reloads. First I rake some of the coals to the front of the firebox as suggested here and elsewhere. I then squeeze small/medium size logs as tight as possible on the first "level" of the firebox. Then I take ashes from my ash bucket and sprinkle some between each logs to restrict air flow. I stack a second layer of larger logs on top of that and again I add some ashes between the logs. So far it has been working extremely well, I'm impressed.

 

[Vg3200p]

@flamontagne I don't have this stove but had a similar problem that took me about 3 weeks to figure out. Have you located where the stove draws in the secondary air? Does this stove have removable jackets on the side? My stove had 6 extra secondary air holes hidden underneath the jackets. I had to block off 4 of them and the main secondary ports to make mine controllable. Just a thought. I know how scary/frustrating a way to hot runaway stove can be