Super 27 question

[MontanaSam]

Hello all; have been burning wood in a new Super 27 for 2 months now and getting ready to settle in to a good Montana winter, lots of game in the freezer and lots of wood in the shed.

I am having a bit of "trouble" damping the stove down enough to maintain a long, slow burn. I am currently burning all sorts of softwoods. It seems that there is no difference in air intake adjustments when I move the lever from "start", and on the "low" position, the flames certainly calm down quite a bit, but there is always still very active burning. This morning, after a short warming fire, I loaded the stove with big larch splits, set the stove to it's lowest air instake setting, and went out for a few hours in the woods. Returned in less than 4 hours and nothing but ash, warm house. Any advice on maintaining longer burn times? I do not have a damper on the chimney.

Thanks

 

[begreen]

It's usually a combination of things that leads to successful long burns. Some things that can affect the burntime are too strong draft, too dry wood, not enough wood, too early reloading on a too hot coal bed, too much air to the fire, air not closed down soon enough.

How tall is the flue system on the stove? Are the coals burned down before reloading? Is the stove packed tightly with little splits in between the larger splits? How soon is the air supply reduced after reloading?

 

[Off Grid Stoves and More]

The Super 27 should give you up to a 8 hour burn time according to the testing laboratories which is all dependent on the type of wood you are burning. If you stick with hardwoods, (Oak, Alder, Maple or Madrone) examples of woods native to west coast,not sure of your area, You will receive the longest burn times. The burn time can also be affected by the amount of draw being created by outside pressure, wind is normally the cause. I did look up "Larch" and it says it is the hardest of the soft woods, LOL The Super 27 is a great stove and should give you all the heat you are looking for. A inline pipe damper can assist with slowing down the draw, but the drawback is that it can build up creosote faster than without due to colder flue conditions of slowing down the smoke. Be cautious though, I have seen plenty of chimney fires over the years due to pipe dampers by the simple fact that they create more maintenance needed of sweeping the chimney and being over looked. The pipe damper will create more heat in your stove by the back pressure which is a bonus.

 

[begreen]

It takes time to dial in one's technique for maximum burn times. Our next door neighbor has the same firebox in the Spectrum. He gets 8-10 hr burntimes with doug fir and has coals for 10-12 hrs. Larch is usually very good fire wood. Something is not right. You can expect longer than 4 hr burn times. This stove was made in and for softwood country.

 

[jigger47]

I started out last year with a new super 27. I was having similar issues and had a post about it. I'll try and find it and post the link.
https://www.hearth.com/talk/index.php?threads/New-install-PE-Super-27.136103/

Page 1 has the burn info for longer burn times.

 

[MontanaSam]

Thanks for the advice so far. I am ruling out draft issues...the chimney runs straight up from first floor, through the middle of the second floor and out near the peak of the roof. No back drafting or puffing or any chimney issues so far, stove is drawing very well, starts are a breeze.

Super 27 owners....do you notice a significant change in fire activity when you move the air intake lever? What I'm getting at is the only difference I notice is between "start" position, and fully closed to "low". There doesn't seem to be anything in between, fire does not change and burns hot and fast. On "low" the fire burns very actively and fast, even with a fresh load of dry fir and larch splits.

 

[begreen]

The possibility of too strong draft may be an issue worth considering. How many feet is it from stove to the chimney cap?

Describe how the stove is being run. Are the coals burned down before reloading? Is the stove packed tightly with little splits in between the larger splits? How soon is the air supply reduced after reloading?

 

[sigepsb]

I have a Super insert and I think the workings are pretty similar. I notice the same thing, that the air control doesn't have as much effect over most of its range, that it does in the last inch or so. Compared to my Napoleon's at my cabin, the PE is just not as controllable. I'm sort of along for the ride. It does put out lots of heat, burns real clean and gets pretty long burn times- it's just more of a process where I get it started, close the air down and hang on for the ride which sometimes gets pretty hot.

Here's another thought. It's been really dry out West for a few years. I also burn some softwoods, such as pine. My cheap moisture meter would read 8% or sometimes wouldn't be able to read at all it was so low. I had an industrial hygenist, with a very expensive moisture meter, confirm that my wood is single-digits moisture wise. Has Montana also been this dry? The super-dry softwood may be accounting for some of this. I try and use the larger splits and hardwood for overnight to help. Has Montana also been very dry for a few years?

 

[MontanaSam]

Yes, drought conditions in MT this year, burning very very dry standing dead soft woods, wave a match at it and it bursts into flame.

The stove puts out a ton of heat, can warm my 1200 sq. ft home up 10 degrees in under an hour easy. I have been burning a really hot fire of kiln dried (3% moisture) wood flooring scraps every morning, and then load larch and fir onto that coal bed, let the logs catch, then choke it down all the way and I get only about 4-6 hours of burning.

Stove to chimney cap is about 22'

 

[MontanaSam]

Just opened up the bottom of the stove to take a look at the air intake valve set-up and noticed that on the lowest setting, there is still a sizable hole in the intake opening, perhaps 1.5" square, along with an opening towards the rear of the stove, also maybe 1" square in size. Before I modify anything I want to let a few cold months pass and really understand how the stove works with the wood I'm burning.

 

[Seanm]

When you reload your larch are you raking the coals forward? Begreen mentioned packing the stove, do you do this? I praise larch on hearth on a regular basis and also use it in my 27 for overnight burns. I will load the stove around 11 pm with larch and still have coals in the morning to rake forward and fill the stove 3/4 with fir or lodgepole. In this kind of weather that can be done between 9-10 am. Once the cold weather hits the draft will increase and we will have to reload an hour or so sooner. I will fill the stove up starting with two splits on the bottom and then stack it as tight as possible. I will then go to the garage and split a few smaller pieces to fill in some of the holes. I use an IR for my stove top temperature and typically have it closed down by 475 because we know it will continue to climb after this point. I'm about the same as you with amount of pipe.

 

[BurningBrutus]

I had the same problem on my super 27 insert, here is your answer, you have to bend the stop for the air control under the insert so the lever covers more of your stove hole inlet, this will fix all your problems, problem solved, it was night and day for me, your welcome

 

[jeff_t]

Ya. My stove is old, but IIRC the primary air inlet gets covered almost all the way, and probably 75% or more of the secondary air intake. I've never looked under a new stove, but the linkage and sliders are clearly visible on mine.

The stove is pretty well known as an easy breather. Two story, straight up chimney might need a key damper to slow it down a little.

Do you monitor flue gas temps?

 

[Starstuff]

I had the same problem on my super 27 insert, here is your answer, you have to bend the stop for the air control under the insert so the lever covers more of your stove hole inlet, this will fix all your problems, problem solved, it was night and day for me, your welcome

Whoah, could you explain this a little more? Like, uh, how to do it?

Sounds like it might solve the issues I'm having as well... My Super insert rages like a damn inferno even with the air control all the way closed. I tried plugging the boost air, but that just killed the fire entirely. (Boost air appears to be very necessary to maintaining a burn.)

Also, do you have the inside air intake cover removed or left on?

 

[begreen]

Read this article that talks about the issue and options. You'll note the example shown for the air control is the PE. Our stop is bent over a bit so that about 1/4" air gap remains. Normally I don't take it all the way to the stop unless burning very dry wood or it is very windy outside.
http://www.gulland.ca/florida_bungalow_syndrome.htm

By inside air intake cover, do you mean the boost manifold cover? If yes, don't remove that.

 

[Starstuff]

Read this article that talks about the issue and options. You'll note the example shown for the air control is the PE. Our stop is bent over a bit so that about 1/4" air gap remains. Normally I don't take it all the way to the stop unless burning very dry wood or it is very windy outside.
http://www.gulland.ca/florida_bungalow_syndrome.htm

By inside air intake cover, do you mean the boost manifold cover? If yes, don't remove that.

Yeah, I took a look and I see the mechanism now. Looks like a thick piece of metal, and without pulling the stove out and flipping it on side, I'm trying to think of options. It needs to be pulled instead of pushed, so I can't just whack it with a hammer and long screwdriver.

The inside air cover is a cover underneath the stove that can be taken off to allow air to enter from near the front of the stove (close to the room) than the back. Actually, I've found that you have to remove this cover in order to bend the tab, at least on my the E-design of the Super insert.

 

[begreen]

Vice grips clamped on the very tip of the tab will bend it. I did this with the stove in place. Took about 10 seconds but this was with a freestanding T6.

 

[Starstuff]

Vice grips clamped on the very tip of the tab will bend it. I did this with the stove in place. Took about 10 seconds but this was with a freestanding T6.

I was unsure I'd be able to get the vice grips through the tight opening, but they managed to just slip under. Was having a hell of a time bending the tab until I realized I could take off the lever-guiding panel that was making it difficult to get good leverage .

So now I've got the tab bent enough so that probably 1/8 to 1/16" is still open when the lever is all the way right. I don't know how this is going to affect the behavior of the stove. If this air intake feeds both the boost and secondary air, then I'm in trouble. But if it is only for the primary air, then Eureka! Won't know until I build a big fire tonight.

If anyone has a schematic showing the various air channels on the PE super insert, that would be much appreciated

 

[BurningBrutus]

I did mine with vice grips as well, i did not have to pull my insert out at all, very easy to bend. Once done you will have a brand new stove and will have to re learn how to use your stove, best thing i ever did, i was having the same issue with not being able to shut it down enough. Seems like PE should make a permanent fix for this, just let it close down more PE.

 

[BurningBrutus]

oh, and leave cover on.

 

[Starstuff]

I did mine with vice grips as well, i did not have to pull my insert out at all, very easy to bend. Once done you will have a brand new stove and will have to re learn how to use your stove, best thing i ever did, i was having the same issue with not being able to shut it down enough. Seems like PE should make a permanent fix for this, just let it close down more PE.

Yep, I got it done. Thanks for the tip. Never would have thought of that.

Can you completely cover the air inlet now, or did you leave a little bit of a gap?

 

[begreen]

It should just affect the primary air. The secondary air intake is in the back of the stove, but it sounds like they have put a duct on the insert to deliver air from the front of the stove. Is that correct?

I did mine with vice grips as well, i did not have to pull my insert out at all, very easy to bend. Once done you will have a brand new stove and will have to re learn how to use your stove, best thing i ever did, i was having the same issue with not being able to shut it down enough. Seems like PE should make a permanent fix for this, just let it close down more PE.

PE stoves go in all sorts of situations and varied chimney heights. A lot of them are single story with short chimneys which will benefit from more air.

Most importantly they are set up to pass EPA testing as best as possible.

 

[Starstuff]

It should just affect the primary air. The secondary air intake is in the back of the stove, but it sounds like they have put a duct on the insert to deliver air from the front of the stove. Is that correct?

PE stoves go in all sorts of situations and varied chimney heights. A lot of them are single story with short chimneys which will benefit from more air.

Most importantly they are set up to pass EPA testing as best as possible.

Given the dramatic variation burn performance, they might want to make it so this is at least customizable by the buyer/installer, and a section added to their install manual, which is not the greatest to begin with...

 

[BurningBrutus]

It still leaves a little of the hole open, to be honest i dont know how much, its been a while since i did it.

 

[Starstuff]

It should just affect the primary air. The secondary air intake is in the back of the stove, but it sounds like they have put a duct on the insert to deliver air from the front of the stove. Is that correct?

That is correct. There is a channel that runs the entire length of the bottom of the stove. If you take the outside air (referred to as "o/a" in the manual) cover off, it creates an opening at the front of the stove. With the cover on, it will pull from the back of the stove. I believe it's meant to be left on for O/A, since whatever O/A inlet used is most likely going to be in the back. However, as we know all to well, the stove breathes well, and you can do just fine with the O/A cover left on even for room air.

It still leaves a little of the hole open, to be honest i dont know how much, its been a while since i did it.

Guess it's time to build a fire and find out! I'm excited to see if this solves the issues I've been having and I'll finally see those legendary 10 hour burn times.