Super 27 runs hot!!!

[Cudos]

I just bought a stove top thermometer (imperial) and was I surprised. Went to the cabin this weekend and loaded the stove cold, inside temp was 3.6c. I did what I always did to get the cabin heated fast, load the stove and let her go. In 35-40 minutes it was at 700f, (according to the thermometer) then hit just under 800f and cruised there until I turned the air down. Even still it ran at 700f. The only way I could get this stove into the 300-400 optimal range was to let the fire die down to almost a coal bed only.

I had no overheat issues that I could see. Could i have a crappy t/stat? I have about 25 feet of straight through chimney maybe its a draft thing. Anyways If the temps are correct am I flirting with danger even though the stove seems to love cruising at high temps.

Cheers

 

[begreen]

That's like saying my car goes too fast when I hold my foot down on the gas. This is not a stove problem, it's the driver. Those temps are too hot and risking overfire or potentially shortening the stove's lifespan. The air should be closed down sooner. Don't wait until it gets to 700, start closing it down when it gets to 400-500. The stove top temps will still rise, but you want them to settle out around 700.

 

[Cudos]

That's like saying my car goes too fast when I hold my foot down on the gas. This is not a stove problem, it's the driver. Those temps are too hot and risking overfire or potentially shortening the stove's lifespan. The air should be closed down sooner. Don't wait until it gets to 700, start closing it down when it gets to 400-500. The stove top temps will still rise, but you want them to settle out around 700.

Thank-You, I am new burner so i appreciate the advice. I thought it was ok to leave the air open as long as needed, since I was trying to warm a ice cold cabin as fast as possible. I will close it down sooner to try and regulate it better. I was just surprised that it got that hot after 35 minutes.

Cheers

 

[precaud]

Those temps are too hot and risking overfire or potentially shortening the stove's lifespan. The air should be closed down sooner.

I have to disagree here. There is absolutely nothing wrong with 700F or so on a Super 27, 700-750F or so is normal cruising temps. Running for an extended time with the air wide open is not wise. But those temps are completely normal for this stove, and others like it.

 

[albertj03]

I believe the heat ranges on the magnetic thermometers are meant to be for the stove pipe, not the stove top. I have a Super 27 as well and it loves to cruise around 700 stop top. You may want to get another one and place it about 18" up on the stove pipe.

 

[Cudos]

Thanks guys, I do have another probe to install on the flue, its for double wall pipe so that should work. The stove top stat I have says its for single wall stove pipe but the guy said I could use it for stove top. ? who knows, I do know that this super 27 seems to love cruising wide open and I haven't seen any warning signs, noise, glowing parts or a run away fire. I do respect the fact that I have to dial back sooner than later though and not run it full open all the time.

Its so tempting just to let the stove go when the cabin is sooo cold

 

[precaud]

Cudos, no stove "likes" to run wide open, and especially not a modern one. Under normal use, once your fire is burning briskly and chimney draft is re-established, your air control should be MUCH lower than wide open - more like 1/3 open or less. The stove will operate more efficiently and put less heat out the chimney.

 

[begreen]

Good point. When running with the air control wide open after the wood is fully burning, the flue temps will show that a lot of heat is just going up the chimney. This is wasting wood. By turning down the air control a bit sooner you will see the flue temps drop and the stove tops rise. That's the zone you want to hit.

 

[Cudos]

Thank-You guys,

I will get the fire going good then dial back to about a third, this should take about 20 minutes I think, hopefully from there I can reach a temp of about 400-500 and just cruise from there. I always thought the hotter my fire was burning that meant more heat was coming into the house, not up the stack. It does seem to make sense though, that if the draft is really strong with a wide open fire then most of that heat would be sucked right out the flue.

Thanks all!!

 

[dispatcher101]

I have to agree with all the prior comments. My T5 has the same fire box as your super 27. I run the stove wide open to about 400. I then close the air down between 1/2 and 2/3 depending on how the fire responds. I think you will be surprised to see how quickly the temp continues to climb. At around 500-550 I shut the air all the way down. My t5 cruises at around 650 very happily. I think that the 400 degree sweet spot you mentioned may be a little low. Each stove/setup has its own characteristics and with time you will figure it out. Good luck.

 

[BrotherBart]

As you move the primary air control down the balance of the air being pulled into the stove shifts to the secondary air being pulled through those holes in the baffle in the top of the firebox. This provides the oxygen needed to burn the smoke coming off the wood and provide a lot of heat that would have been lost as smoke up the chimney if primary is left open.

 

[albertj03]

You can absolutely use the magnetic thermometer on the stove top. Just don't pay any attention to the zones that it shows as those are meant to be indicators for the stove pipe, not the stove top.

 

[precaud]

BB, normally that's true, but not with the 27. It's one of the few stoves where the secondary draws off the same plenum as the primary.

 

[oldspark]

Good point. When running with the air control wide open after the wood is fully burning, the flue temps will show that a lot of heat is just going up the chimney. This is wasting wood. By turning down the air control a bit sooner you will see the flue temps drop and the stove tops rise. That's the zone you want to hit.

That is one thing my Summit does not do, when I start to close the primary air the stove top does not rise much at all, sort of hangs at the same temp, I have read other posts where some peoples stove do the same thing but have not heard of any ideas on why this is. I do believe this is why I am not getting the heat out of the the stove that other people do.

 

[albertj03]

BB, normally that's true, but not with the 27. It's one of the few stoves where the secondary draws off the same plenum as the primary.

Does that mean that the amount of primary and secondary air flowing into the stove is always the same?

 

[precaud]

Now spark... your stove is working fine, remember? And you're really happy with it, right? So go back to your chair and enjoy the fire.

 

[BrotherBart]

BB, normally that's true, but not with the 27. It's one of the few stoves where the secondary draws off the same plenum as the primary.

Oh how nice it would be if they all did that.

 

[precaud]

Does that mean that the amount of primary and secondary air flowing into the stove is always the same?

No, it means the ratio of pri to sec doesn't change.

BB - Oh how nice it would be if they all did that.

Aye, captain...

 

[albertj03]

Does that mean that the amount of primary and secondary air flowing into the stove is always the same?

No, it means the ratio of pri to sec doesn't change.

BB - Oh how nice it would be if they all did that.

Aye, captain...

I still don't get it, at a certain point doesn't there need to be more secondary than primary air? Why is it that the way the Super 27 works is more desirable?

 

[BrotherBart]

Does that mean that the amount of primary and secondary air flowing into the stove is always the same?

No, it means the ratio of pri to sec doesn't change.

BB - Oh how nice it would be if they all did that.

Aye, captain...

I still don't get it, at a certain point doesn't there need to be more secondary than primary air? Why is it that the way the Super 27 works is more desirable?

Because the primary air down low is driving the gasification that feeds secondary combustion up top. And also after secondary craps out around a third of the way through the burn something down low needs to burn the rest of the load.

 

[precaud]

I still don't get it, at a certain point doesn't there need to be more secondary than primary air? Why is it that the way the Super 27 works is more desirable?

When the primary air control is turned down (on any stove), the air velocity out of the airwash reduces. So more of the primary air automatically gets pulled up toward the secondary chamber (above the baffle) and becomes essentially secondary air, which means less is needed from the secondary.

When you close the air control down all the way, it also reduces the secondary air, which is why that firebox has such long burn times. Less airflow = longer coals life.

The super-series was designed taking all this into consideration - good engineering.

You can achieve the same thing with any stove by adding a secondary air shutoff to it. I do it to every stove I own.

 

[albertj03]

Wow that's great to know. I do enjoy the long burn times and great heat the stove puts out.

 

[precaud]

It really is an excellent design - pity I don't own one... :-/

 

[Cudos]

Wow, learning lots here about the Super 27, many thanks to all of you for your replies. I now have a better understanding on how to manage my S27 and a new appreciation for its design.

What can I say, I'm a newb and this stove has been treating me well despite my lack of knowledge.

Cheers

 

[lillyrat]

Good point. When running with the air control wide open after the wood is fully burning, the flue temps will show that a lot of heat is just going up the chimney. This is wasting wood. By turning down the air control a bit sooner you will see the flue temps drop and the stove tops rise. That's the zone you want to hit.

That is one thing my Summit does not do, when I start to close the primary air the stove top does not rise much at all, sort of hangs at the same temp, I have read other posts where some peoples stove do the same thing but have not heard of any ideas on why this is. I do believe this is why I am not getting the heat out of the the stove that other people do.

My Summit will do the same thing but only when I load it on a small coal bed or if I have a less than "dry" piece of wood in there. I can actually predict if this is going to happen by how the fire take off and how long I have to leave the air all the way open to get the flue up to 400-500. Actually happened last night and had to turn the stove up again after shutting it down to let it get good and warm before I shut it back down.
Now the way my fires usually go, I don't get any heat until I start to turn the stove down to at least half air if not 1/4.. I don't see how people drive their stove with only stove top thermometers. I would have external flue temps of >600 degrees if I were to wait for the stove top to get to 400 before shutting it down.